Community Work Data Collection

Offline Data Collection

For our community projects executed by Malati Vaidya Smruti Trust and Water Group, we often need data collected from various locations like lat long and dimensions of an existing bandhara wall (weir) on a river, or sequencial path of lat long points from a borewell to a nearby school.

This data can be captured on smartphones which are commonly available with local people nowadays, using various apps like My Tracks. But most such apps need the internet / data connection to be always enabled / available on the phone. At most of the locations which are remote areas, mobile network and data connectivity are not available.

मालती वैद्य स्मृती ट्रस्ट आणि वॉटर ग्रुपद्वारे राबविल्या गेलेल्या आमच्या सामुदायिक प्रकल्पांसाठी आम्हाला अनेकदा वेगवेगळ्या ठिकाणांहून माहिती गोळा करावी लागते जसे की एखाद्या अस्तित्त्वात असलेल्या बंधाराच्या भिंतीच्या जागेवर जाऊन त्याची लांबी, रुंदी, अक्षांश आणि रेखांश नोंदी घेणे किंवा एखाद्या बोअरवेलपासून शाळेपर्यंतचा मार्ग आणि त्यावरील नोंद करावयाचे अक्षांश आणि रेखांश.

माय ट्रॅक्स सारख्या विविध अ‍ॅप्सचा वापर करून आजकाल स्थानिक लोकांकडे सहज उपलब्ध असणाऱ्या स्मार्टफोनमध्ये हा डेटा नोंद केला जाऊ शकतो. परंतु अश्या बर्‍याच अ‍ॅप्ससाठी फोनवर उपलब्ध असलेले इंटरनेट / डेटा कनेक्शन गरजेचे असते. दुर्गम भागातील बर्‍याच ठिकाणी, मोबाइल नेटवर्क आणि डेटा कनेक्टिव्हिटी उपलब्ध नसते .

This requires that there needs to be some offline data collection mechanism, which will also allow submitting the data to central data server/repository whenever the data connectivity is available.

या समस्येवर मात करण्यासाठी एखादी ऑफलाइन डेटा संकलन प्रणाली असणे आवश्यक आहे, ज्याद्वारे जेव्हा कधी डेटा कनेक्टिव्हिटी उपलब्ध असेल तेव्हा ऑफलाईन पद्धतीने नोंद केलेला डेटा सेंट्रल सर्व्हर/रेपॉजिटरीमध्ये पाठवता येऊ शकेल.

We find that, ODK collect – which is a free to use app, can be the most (if not the best) suited and user friendly option for this purpose.

थोडी शोधाशोध केल्यावर आम्हाला असे आढळले की, ओडीके कलेक्ट – जे वापरण्यासाठी विनामूल्य आहे, या कामी बरेचसे योग्य आणि वापरकर्त्यांच्या दृष्टीने अनुकूल पर्याय होऊ शकते.

Pre-requisites for the End User

साधारण वापरकर्त्यांसाठी पूर्वतयारी

End User is a person who will be given the task of capturing data using the forms created by admin user.

  • User should have an android based smartphone with mobile data or wifi connection that has to be operational from his home or one such place.
  • User needs to have created his Google email id and it needs to be active.
  • Google drive app installed on phone.
  • ODK Collect app installed and configured on phone.

साधारण वापरकर्ता ही अशी व्यक्ती आहे जी उपलब्ध फॉर्मचा वापर करुन माहिती संकलनाचे (डेटा कॅप्चर) काम करील.

  • वापरकर्त्याकडे मोबाइल डेटा किंवा वायफाय कनेक्शनसह Android आधारित स्मार्टफोन असावा. डेटा /वायफाय कनेक्शन त्याच्या घरातून किंवा किमान एका तरी ठिकाणी कार्यरत असणे गरजेचे आहे.
  • वापरकर्त्याने त्याचा Google ईमेल आयडी तयार करणे आवश्यक आहे आणि ई-मेल सक्रिय असणे आवश्यक आहे.
  • फोनवर Google ड्राइव्ह अ‍ॅप इन्स्टॉल केलेले पाहीजे
  • ओडीके कलेक्ट अ‍ॅप फोनवर स्थापित आणि सेट-अप केलेले पाहीजे.

Setting up ODK Collect App (All Users)

ODK कलेक्ट अ‍ॅप सेट अप करणे (सर्व वापरकर्ते – साधारण तसेच अ‍ॅडमिन वापरकर्ते )

These steps, as a part of Setting up ODK Collect app, require data connectivity enabled on your mobile phone.

On your smartphone go to Play Store, Search app by name ODK Collect, Download and install the app.

When the ODK Collect app is started it will show its home page as below.

ओडीके कलेक्ट अ‍ॅप सेट-अप करताना आपल्या मोबाइल फोनवर डेटा कनेक्टिव्हिटी सुरू केलेली असणे आवश्यक आहे.
आपल्या स्मार्टफोनमध्ये प्ले स्टोअरवर जा, ओडीके कलेक्ट नावाचे अ‍ॅप शोधा, अ‍ॅप डाउनलोड करा आणि इन्स्टॉल करा.
जेव्हा ओडीके कलेक्ट अ‍ॅप सुरू होईल तेव्हा खालील प्रमाणे मुख्य पृष्ठ दिसेल .

In right top corner menu of the app, you can see options as below.

Select General Settings

Select option Server

Select Type and Choose the value Google drive,Google sheets

Select option Google account and when prompted choose or type your Google email id.

In General Settings select Option User and device Identity, a new page will show up as below.

In this page select option Form metadata

A new screen will show up, in this screen select options User Name, Phone Number, Email Address one at a time and set correct values for each of these three parameters.

For user name make sure that your name (say first name and last name seperated by space or underscore character) will not duplicate with any other person’s name working on the same survey.

Include underscore or suffix (say 2001) or simply enter your Gmail id in the User Name field, so as to always make sure of it to be unique.

The fourth parameter is Device ID, let the value whatever it is set on this parameter as a defualt, be left as it is.

Fetching Form Master Data (End User)

Fetching Form Master Data requires data connectivity enabled on your mobile phone.

After the ODK Collect app is configured as given in previous step, then on the main page of the app click button Get Blank Form.

It will show a popup message with some text saying Reading Files.

After some time it will show contents of the Google drive for you as the Google drive user. If you are a form designer yourself and if you have created any forms, then the same will be shown here in the list.

In the lower side buttons click Shared with Me, this is required so as to get access to forms that other form designers / admin users may have shared with you.

Once clicked it will show Reading Files message.

Then it will show the list of files available /accessible to you as may have been shared with you.

It will show Files and Folders shared with you by other Google Drive users. A form file is most often a .xml file, as seen in few samples in the above image. Please contact your team lead / admin user in your group who can give you the exact names of the working forms for getting access to those forms.

Once the form name/form file name is know to you, select the form file on which you have been asked to capture the data, and then click Download Selected button at lower part of screen. It will show some saying – Fetching files, let it complete the processing.

After successful fetching of the form, it will show success message as below.

Capture Data At Actual Site Location (End User)

Data capture work can be performed entirely in offline mode and network connection and mobile data on the phone is not necessary.

If the survey includes any questions or data elements to capture Geo Location point (lat long) then GPS on the phone MUST BE enabled with high accuracy.

On main page of the ODK Collect app, click Fill blank form button. On the following page the forms fetched/downloaded so far will be displayed.

Select a form that you want to use for data capture, then the app will go on asking questions from that form sequentially, and it will allow navigation through the questions.

Questions and their response entry fields are different based on each question type as may have been configured by the Admin User.

Please go on responding with appropriate answers till the end.

Answer/response to some of the questions may be mandatory so user can not go to next question untill values are captured.

A single Geo location point where latitude and longitude needs to be capture will appear something like below.

With GPS enabled on your phone, wait for some time till the accuracy improves to 2 or 4 meters or better and then click Save GeoPoint button. Image shown below only a sample, and was captured indoors when no GPS satellite was accessible to the phone, hence it shows very poor accuracy of more than 20 meters.

Once saved the GeoPoint will appear like below, after ensuring the accuracy value, proceed to Next or capture the point again by clicking the button Change Location.

Next sample question is for capturing a GeoTrace (multiple Geo points).

Most likely if mobile network and data connection is not available then the map may not show at all or will show with very coarse resolution, refer next image.

It is important to use the correct method for capturing the points in a Geo Trace. By clicking the first icon with + sign, at the right side edge of the page, select the Automatic location recording option, specify values for Recording Interval and Accuracy Requirement as shown and then click Start.

This is to be used while the end user walks around the object / entity being surveyed. For example if the user is capturing the GeoTrace near an open-well or a river, then the user needs to walk around the boundary with the auto option enabled. You can see that the ODK Collect app will record points continously every 10 or 20 seconds.

Once the boundary of interest is traversed as adequate then click the lowermost option for save which shows a disk icon.

After save click the values captured are displayed in a page like below.

Go throgh all the questions in the survey and capture the data to the fullest possible detail and accuracy. Please follow the instructions that may have been included by the Admin User for each question.

There can be various question types included in the survey as below.

  • Text
  • Number
  • DateTime
  • Date
  • Image
  • Audio
  • Video
  • Lat long – GeoPoint
  • Lat long list – GeoTrace

At the end of the survey questions the ODK Collect app will show a button Save Form and Exit, click that button to save the data captured.

Until so far the data captured is on the user’s phone and yet to be sent to the central common data repository/storage.

Send Form, Submit Data (End User)

Once you are done with the data capture as above you can / should submit the data.

For this you need mobile/data connection on your phone.

This activity can be performed from any location other than the survey site where mobile network or wifi connection is available and enabled on your phone.

Once your phone gets the data connection, then on main page of the ODK Collect app, click Send finalised form button..

It will show a page where all the form which can be submitted will be displayed. Select one or more forms which are ready to submit and click Send Selected button.

It will show Sending Form message, and finally it will show success.

Form submission success.

If any error occurs, please take a screenshot on your phone and send it to the admin user or entire team, so that suggestion about what to do on such error can be given.

User can view all the submitted/sent forms. By clicking the button View Sent Form on the home page of the ODK Collect app.

Any of the sent forms can be selected/touched/clicked and in the next page the app will show list of all questions in that form with captured data / answers shown briefly.

Pre-requisites for Survey Admin user

Admin user is a person who will prepare the survey questions and release the survey to the end users for data capture.

For each form to be used for data capture, below are the pre-requisites for admin user, these are in addition to all the prerequisites as applicable to the End User.

  • Create a blank Google spreadsheet in Google drive.
  • In Google Drive share the spreadsheet to all the data capture users, by adding their Google email Id.
  • Note down / copy the sharable URL of the spreadsheet file.
  • Create a Form layout using online form builder utility at this web site This will require a login user id for yourself to be created first time.
  • Add the desired type and sequence of various questions.
  • Include the meta data system fields like user and phone number.
  • Specify the spreadsheet URL in the form properties – submission URL of the newly created form. Each form must have a different and distinct spreadsheet associated with it.
  • Export the form to local filesystem as XML format
  • Upload the form XML file in the Google drive.
  • In Google drive Share the form XML file to all the data capture users, by adding their Google email Id.
  • Avoid modifying the form design once the form is released for data capture and some data is already captured by the End Users.
  • If an existing form must be modified, deleting or renaming any existing question / field shall be avoided. Label and captions can be altered.
  • If a new question / field is to be added then corresponding field name must be added to the data capture Google spreadsheet as a new column after all existing columns and name of the new question / field needs to be manually entered as column label.

Survey Form Design (Admin User)

Create a form using ODK Build webpage available at this site

It is an interactive user interface for creating a data capture/survey form with various types of input fields or survey questions that can be added to the form. The instructions for form creation are not given here in details, and admin users are encouraged to explore the form builder web page, use the online documentation / help and get started with real forms that they want to create.

It is seen that it is best for the Admin users understand the form builder by doing hands on work.

Overall – How it Works / Conceptual Details

So far the activities to be carried out by End User and Admin User were exaplained.

For a given form, it may be so that one or more users are asked to capture data using the same form but for various different survey objects (locations or sites), as below.

  • User 1 – Location 1, Location 2
  • User 2 – Location 3, location 4 and location 5
  • User 3 – Location 1, location 3 and location 6

The data captured by multiple users as above will result in 8 instances of the same form captured on 3 different mobile phones of the 3 different end users. Notice that for Location 1 and Location 3 two different users were asked to capture the data, this may be intentional or otherwise.

All this data gets saved into respective mobile phones and when forms are sent by the users, it gets saved on the Google drive of the form creator user in a structured manner. There will be 2 each responses /datasets captured for Location 1 and Location 3, whereas other locations will have only one dataset.

The data captured from all users after they sent their respective forms needs to be programmatically fetched and interpreted, organized, processed and saved into some databse where it can be displayed or represented in a manner required by the project team.

With a question of type GeoTrace below processing can be useful to better understand the data captured.

  • To display the set of points as a track on Google map for all the points.
  • To calculate the perimeter distance and area of the boundary identified by the points.
  • To group various survey objects (say water-bodies) by their range/span of GeoTrace values.
  • All of the above.

We are in process of implementing a utility which can do such type of data processing using the data collected in ODK forms.

This will be deployed in our web site and will be made available to the logged in users. The users will need to permit the portal to access their respective Google drive files.

ODK Collect also works with a backend server instead of Google sheets, but that most often is a paid option which requires some server hosting and associated infrastructure management. Using Google sheets as the data capture mechanism is easier and free of cost as of now. Hence the same is highly recommended for community work and projects.

Please use ODK Collect app as explained above and provide your comments / feedback on this article.

Thank you.

Solar Energy

घरगुती वापरासाठी सौर विद्युत प्रकल्पाचा आराखडा

प्रकल्पाची उद्दीष्टे

सोलर पॅनल च्या सहाय्याने वीज निर्मिती करून त्या विजेचा वापर घरामध्ये करता यावा यासाठी महावितरणच्या नेट मीटरिंग पॉलिसीनुसार प्रकल्प सुरू करणे.

विजेचे बिल जवळपास शून्य रूपये (स्थिर आकाराव्यतिरिक्त – वहन आकार, वीज शुल्क इत्यादी घटक धरून) यावे यासाठी सोलर पॅनेल्सची आवश्यक ती क्षमता ठरविली जाईल.

प्रकल्प उभारण्याचा प्रारंभिक खर्च पार्टिसिपेटरी पद्धतीने केला जाईल. त्यासाठी सेवाभावी संस्था आणि ज्या घरांमध्ये वीज वापरावयास द्यावयाची आहे त्यांच्याकडून काही प्रमाणात निधी उभारला जाईल.

प्रकल्पाचा दरमहा येणारा खर्च (यामध्ये प्रामुख्याने महावितरणला भरावयाच्या वीज बिलाची रक्कम समाविष्ट आहे) वापरकर्त्यांकडून भागविला जाईल. या प्रकल्पामध्ये बॅटरीची आवश्यकता नसते त्यामुळे दर दोन-तीन वर्षांनी बॅटरी बदलावी लागते तो खर्च इथे लागू होणार नाही.

या प्रकल्पाचा फायदा असा की वापरकर्त्यांना विज बिल खूप कमी येईल आणि त्यामुळे वीज बिल भरण्याची टाळाटाळ करण्याचे प्रमाण बरेच कमी होईल, अशा पद्धतीने हे महावितरण साठी सुद्धा सोयीचे राहील.

प्रकल्पाची संकल्पना

दोन किलोवॅट इतक्या क्षमतेचा सोलर नेट मीटरिंग प्रकल्प करावयाचा आहे. याचा खर्च साधारणपणे ९० ते ९५ हजार रुपये इतका होतो, यामधून दरमहा 210 युनिट इतकी घरगुती वापराची (सिंगल फेज) वीज उपलब्ध होते.

महावितरणच्या LT I (B): LT Residential या टेरीफप्रमाणे 210 युनिट साठी एकूण बिलाची रक्कम 1441 रूपये अधिक 102 रुपये स्थिर आकार (1543 रूपये) इतकी होईल. प्रतिवर्षी वीज बिलामध्ये 17292 रुपयांची बचत होईल.

या हिशोबाने प्रकल्पाचा खर्च साधारण साडे पाच वर्षांमध्ये वसूल होईल आणि त्यापुढे 18 ते 20 वर्षे मोफत वीज उपलब्ध होत राहील, यामध्ये महावितरण’कडून येणारे वीज बिल (ज्यामध्ये प्रामुख्याने फक्त स्थिर आकार असेल) मात्र दरमहा भरत राहावे लागेल.

प्रकल्पासाठी लागणाऱ्या सामग्रीचा तपशील

या प्रकल्पाकरीता खालील घटक / सामग्री / यंत्रणा आवश्यक असतात, दिलेली किंमत २ किलोवॅट क्षमतेसाठी आहे

  • सोलर पॅनेल्स – ४६००० रुपये
  • ग्रीड टाय इन्व्हर्टर – २३००० रुपये
  • वाहतूक खर्च – ४००० रुपये
  • विजेचा मीटर (नेट मीटर आणि जनरेशन मीटर) – ६००० रुपये
  • एम सी बी स्विचेस, केबल्स, इत्यादी – ७००० रुपये
  • पॅनल बसवण्यासाठी आधाराचे स्ट्रक्चर – ३०००
  • वीजमंडळाची वाढीव लोड फी, सोलर अर्जाची फी आणि मीटर तपासणी फी – ५००० रुपये
  • इंस्टॉलेशन चार्जेस – सहभागामधून करावयाचे असल्यामुळे ० रुपये धरले आहेत.

देखभाल दुरुस्तीविषयी

ह्या प्रकल्पामध्ये बॅटरी नसते म्हणून बॅटरीचे पाणी तपासणे किंवा तत्सम दुरुस्ती लागू होत नाही. तसेच दर २ ते ३ वर्षानी बॅटरी बदलण्याचा खर्च करावा लागत नाही.

पॅनल वर जमा होणारी धूळ १०-१५ दिवसामधून एकदा सकाळच्या किंवा संध्याकाळच्या ऊन कमी असेल अश्या वेळी पाण्याने धुवून काढायला हवी.

दगडफेक आणि चोरी यापासून पॅनलचे संरक्षण करायला हवे. ह्या प्रकल्पाच्या उपयोगितेच्या अनुभवातून सामाजिक जाणीव निर्माण होईल तसतसे हे प्रकार बंद होतील.

याव्यतिरिक्त कुठलाही देखभाल दुरुस्तीचा खर्च नाही .


मोठ्या कुटुंबासाठी, ज्यांची २ – ३ – ४ स्वतंत्र घरे आहेत परंतु जवळजवळ किंवा एकत्र असतील त्यांनी हा प्रकल्प राबवल्यास एक विजेची जोडणी सोलर प्रकल्पासह घ्यावी. जेथे दरमहा विजेचा वापर खूपच कमी किंवा नगण्य असेल तेथे हा प्रकल्प तितकासा किफायतशीर होणार नाही. साधारणपणे दरमहा १८० किंवा अधिक युनिटे वापर असेल तर हा प्रकल्प खूपच सोयीचा आहे.

प्रकल्प बसवण्याच्या खर्चाची रक्कम योग्य आणि शक्य त्या मार्गाने गोळा करून प्रकल्प कार्यान्वित करता येईल.

त्यानंतर दरमहा वीजमंडळाकडून बिल येईल ते वापरकर्त्यांनी विभागून वाटून घ्यावे आणि बिल भरणा करावा.

वीज बिलाची रक्कम कशी ठरविली जाते?

त्या त्या महिन्यामधे सोलर पॅनल मधून निर्माण झालेली वीजेची युनिटे आणि घरामध्ये प्रत्यक्ष वापर झालेली वीजेची युनिटे यामधील फरकानुसार बिल ठरविले जाते.

एखाद्या महिन्यात वीजनिर्मिती जास्त झाली आणि विजेचा वापर कमी झाला तर जास्तीची युनिट आपल्याला पुढच्या महिन्यात वापरण्यासाठी उपलब्ध होतात.

DIY How To IoT

Data Logging for IoT

Internet of Things (IoT) is about connecting various devices (sensors, controllers, display units, alarms and any such instrument/equipment) with each other using public internet and may partly run through private network of the end user.

With this primary capabaility, IoT opens out many opportunities for systems control, remote data monitoring and to execute commands that carry out various operations based on desired conditions.

With improved data connectivity and availability + the reducing prices of electronic devices, IoT is picking up fast and more importantly it is also getting easier for hobbyists and individuals to deploy IoT projects all by themselves.

Besides the hardware and software to implement any IoT project, what is equally important is a consistent and fairly reliable mechanism to receive and store the data points in a (near) real time manner.

Setting up such a data store can turn out costly, but there are many such online services available. For industry grade volumes and quality of service/reliability, such data logging services providers offer various plans with different charge structures.

For hobbyist and DIY users, most if not all these online services offer a free option but obviously with limited resources granted to the user.

A few of the popular service providers are listed below, this is just a very small list.





Let us see how to open an account and create a data logging channel with one of the service providers, namely

Create an account with ThingSpeak

From your computer or mobile phone connected to internet, open the web browser and go to the URL link ThingSpeak SignUp

Enter your email address and Country and First Name, Last Name on the sign-in page, then click Proceed / Next / Continue button. We recommend using the same personal Google email id as you use on your mobile phone google account.

It will warn you about your email address being personal email id. Refer the image below. Please Tick / Select the check box near Use this email… and click Continue button. After this it will display a message mentioning about having sent a link to your email address.

Open your e-mail box and find the mail received from ThingSpeak, check if the email has gone into spam folder. Please ask for resending the mail again, if required, by clicking the Send Me the Mail Again link.

Locate the URL link available in the email that you received and click the link or button or copy paste that URL link in a new browser tab/window. Please keep the previous tab/window of ThingSpeak still open for further use.

This new tab/window (not shown here) which you opened from your email by clicking the verification link / button – will show some message like your account/email after successful verification. This is actually a mathworks account which is another website like ThingSpeak, both of which share common authentication and some other such few features.

After this verification is successful, resume in the previous ThingSpeak tab/window, by clicking the Continue button.

It will take you to sing-up page where you will be asked to specify your user id and password for ThingSpeak login. Please set a valid user id and password for your ThingSpeak account, this is entirely different and not connected with your email address. Remember and/or note down the user id and password for future use.

Then proceed to login to ThingSpeak web site or you will be automatically logged into ThingSpeak.

At the first login it may ask for some additional information like – what purpose you plan to use ThingSpeak for, (refer next image). Please specify non-commercial/ personal use and click ok.

Create Channel

A channel is one identifiable register/data store to capture data.

For example let us say – a user has 2 different locations where he /she wants to monitor the ambient temperature and humidity at every 5 minutes continuously.

To be able to do this the user will setup the needed sensors at the respective locations and data acquired by the sensors will have to be posted to some internet based URL. This URL will receive the data values and store them for later use and analysis.

For this example, the user needs to have two different registers or data stores one per location and each register needs to support at least three fields (namely timestamp, Temperature in deg C., Humidity in %).

So it is like two readings one each for the two locations, comprising of 3 field values each will be received and saved every 5 minutes. That is 576 readings per day and over 2 years it will be around 0.42 million or 420000 readings. Each reading is about 40 bytes say, so just 16 MB of data over 2 years. The data volume for these two datastores is not really that high, but it is important that the datastore has to provide a reliable and continously available mechanism of data logging.

When translated in the terminology of ThingSpeak, this means two channels one each with 3 fields of data are necessary to be created.

Thingspeak allows upto 4 channels to be created by every user having a free account.

So let us see how to create a channel.

After the ThingSpeak login account has been created and successfully logged in, it is required that a new channel be created in the page shown below.

Click the New Channel button, the website will take you to next page.

On this page specify a channel name and select / tick against all the 8 fields shown in the page. Then click Save Channel button. There are other two buttons provided as below

  1. Clear Channel – This clears the old data that may have been captured so far in this channel. It is recommended to not clear the channel unless you are sure that you want to lose the data forever.
  2. Delete Channel – This deletes the channel altogether. It is strongly recommend to not click this ever, especially after any of the field device is using the channel.

Important Parameters of the Channel

Please note down the Channel Id, Name and Read and Write API Keys, as it shows in the web page in the API Keys tab. Once the channel is created the Keys and Channel Id can be used by any device/software so that the data to be collected by any field sensor or device can be posted to the channel. These values can be altered any-time by the the user login who created the channel, but if the channel keys are setup in any IoT device as a part of one time configuration then the altered values (especially the Read and Write API keys) need to be updated in all the devices and programs where the old keys were used.

Verifying the channel

Once the channel is created it can be tested by executing below commands in browser address bar.

Write to Channel

The above comamnd submits and saves one data point with values of two fields to the respective thingspeak channel with matching WRITE_KEY.

Read Channel

This comamnd retrieves 20 data point from the thingspeak channel specified by the CHANNEL_ID

View the data graphically

Thingspeak provides a nice and simple way to view the datapoints. It would be a good activity to explore this part in details to understand what options it gives to view the data, i.e. various types of graph, number of datapoints to be viewed etc.


Mini Weather Station (DIY) – Part 2

Since the concept was posted in the previous blog Mini Weather Station, many friends and readers reverted with various points and questions.

Trying to address them here.

Open for comments and more questions please….

Why DIY Weather station

Do It Yourself gives a full control and understanding about what and how a certain thing is being implemented and it gives a very good hands on experience. Starting with concepts till actual deployment of the gadget, a DIY weather station is your own mechanism to accurately and directly measure and record the climate and climate changes in your area.


What all you need, is below…

  • A ventilated outdoor space, it can be a balcony / terrace, but no direct sunlight and no direct rainfall, at least where the device will be mounted.
  • A continously available WiFi data network.
  • Source of electricity to power the device.
  • Enthusiasm to participate in climate change and related activities.
Weather already on my cell phone.

Yes, smartphones of current generation do have some kind of temperature and weather data displayed on the home screen.

  • There is a very rare possibility that your phone has an actual temperature sensor inbuilt in its hardware Environment Sensors in Phones.
  • Even if there is one such sensor, the temperature displayed from time to time will be at various places including indoor and outdoor as the phone is carried along by the user. And we want to record and track the weather conditions at a specific open ambient place.
  • On most common phones i.e. without a temperature sensor as a part of their hardware, the displayed value is often fetched from some weather services website like AccuWeather
  • Real time data shown from such websites is a fairly complicated calculation, which involves the actual readings from the nearby weather stations (official, public, private, owned by government bodies or institutions) + the data continuously recorded by weather satellites at various locations. Weather satellites donot measure actual temperature but infer the values based on infra-red scanning of the earths surface. How does weather satellite work
  • So the correctness of the temperature displayed on the home screen of your phone is dependent on several factors like the distance from the nearest weather station and weather satellites.
  • Also it is important that we should be able to record data at regular intervals and later be able to compare the values year over year in form of daily, weekly, monthly and yearly min,max and average/median temperatures. Most weather services websites donot provide historical datapoints easily and free of cost.
  • There are not many known/closely located weather stations in India, or at least information about them and their readings are not published.
  • Looking at all the above points, it will be meaningful to have more weather stations through public participatory approach at various places. The data can be valuable in terms of analysing the effect of trees, water bodies, streets congested with traffic, and seasonal changes on the ambient temperature.

Why invest in a weather station?

This is purely optional and voluntary. If anyone wants to participate, it is for his/her own interest in and commitment towards protecting the environment and addressing issues related to the environment. There are many many ways in which efforts can be put in to preserve our environment. Participating in this weather station initiative is just one of them.


The cost of components used in the DIY weather station is about 1100 to 1300 INR. We are happy to assemble/package the components in a working unit and provide to the participants willing to install at their place. The recurring cost of operations is mainly in two parts.

  • Cost of the wifi data – It is estimated that the unit will post 100 characters of data over your local wifi connection every 2 to 5 minutes, that is about 72KB of data per day, lets say not more than 1 MB per day. This is really not much of data for an existing internet connection. With current data quota values supported by most of the broadband and mobile service providers, this is not likely to incurr any additional costs.
  • Cost of electricity to run the device – It is measured to consume between 2 to 3 watts of electrical power continuously, this means that within 14 to 20 days of operation the device will consume 1KWH unit of electricity, amouting to about 4 to 8 INR, which means an additional monthly electricity bill of about 10 to 12 INR
Don’t have a WiFi connection

In such a case, a dedicated mobile-SIM based data connection with a WiFi dongle can be arranged, but that will mean additional costs.

  • One time cost of the dongle device – approximately 1000 INR for most service providers.
  • Recurring monthly cost of service provider – It is approximately 100 INR at a minimum with most of the service providers in India. If there is any service provider which supports much lesser monthly charges with low data quota per day (we are ok even at, as low as 10-20 MB per day, literally) then it will be more practical.
Solar Energy

सौर ऊर्जा आणि आपण – ३

भाग ३ – बॅटरीवर आधारीत सौर ऊर्जा

Part 3 – Battery based Solar Energy

याआधीच्या भागामध्ये आपण घरगुती वापराच्या विजेच्या युनिट बद्दल माहीती करून घेतली. आता आपण पाहूया की सौर विजेचा पर्याय कसा काय आहे ते.

In previous articles we discussed about the units of electricity for household usage. Now we will see how can solar electricity be useful to us.

सोलर पॅनल वापरून वीजनिर्मिती करता येतेच, परंतु सौर ऊर्जेची उपलब्धता दर दिवशी आणि ऋतुमानाप्रमाणे बदलत राहते, इतकेच कशाला, निरभ्र लख्ख सूर्यप्रकाश देणारे आकाश केवळ ५ – १० मिनिटांमधे ढगांनी व्यापले जाऊन सूर्यप्रकाश अचानक कमी होतो. त्यामुळे सोलर पॅनेल्स मधून निर्माण होणारी वीज ही सततच सूर्यप्रकाशाच्या तीव्रतेनुसार कमी जास्त होत राहणार. थोडक्यात काय तर सौरविजेची उपलब्धता आणि आपल्या घरामध्ये त्या त्या वेळी किती वीजवापर सुरु असेल ह्या दोन गोष्टींचा ताळमेळ राहात नाही. याउलट वीजजाळ्यामधून आपल्याला हवी तेव्हा आणि हवी तितकीच वीज वापरायला घेता येते.

Though it is very much possible to generate electricity using solar panels, the instantaneous availability of solar electricity varies every day and across seasons. In fact even on a given day, the clear sky can suddenly turn cloudy and due to reduced sunlight, the solar electricity generation will come down. Thus the solar electricty generated at any time will keep fluctuating based on sunlight. In short there is very less likely to be a match between the solar electricity generated and the electricity needed for consumption. On the other hand if we consume electricity from the electric grid, it can, at all times, supply as much and only that much electricity being consumed.

उदारणार्थ खालील आलेखामध्ये सकाळी साडेसात वाजल्यापासून सायंकाळी साडेपाच वाजेपर्यंत सौरवीजनिर्मितीचे प्रमाण पहायला मिळते आहे. एकतर सूर्य जसा डोक्यावर येऊ लागतो तसे निर्मिती वाढते, परंतु अधूनमधून ढगाळ हवामानामुळे वीजनिर्मिती अचानक कमी झाल्याचे स्पष्टपणे दिसते आहे.

दिनांक – ३० सप्टेंबर २०२० / Date – 30-Sep-2020

ठिकाण – ठाणे ४००६०२ / Place – Thane 400602

सौर पॅनल क्षमता – ४८० वॅट / Solar Panels Capacity – 480 watt

उभा अक्ष – य – वीजनिर्मिती वॅट मधे / Vertical Axis Y – Electricty generated Watts

आडवा अक्ष – क्ष – वेळ तास:मिनिटे / Horizontal Axis X – Time HH: MM

The graph shows how the solar electricity generation varies over time on a typical day.

सौरवीज आणि वीज जाळ्यातली (ग्रीडमधून मिळणारी) वीज ह्या दोघांमध्ये हा मुख्य फरक आहे – हा मुद्दा सतत लक्षात ठेवावा लागतो .

म्हणून सोलर पॅनल मधून निर्माण होणारी वीज साठवून ठेवण्याची आणि नंतर आवश्यकतेनुसार वापरायला मिळेल अशी काहीतरी सोय अत्यावश्यक आहे.

Solar electricity and grid electricity are drastically different from each other in this aspect of availability. and this point needs to be remembered at all times.

Hence it is required that there has to be a way to store electricity generated from solar panels and later make it available for use when needed.

वीज साठवण्याचे सोपे साधन म्हणजे बॅटरी किंवा विजेरी.

ह्यामध्ये वेगवेगळ्या रासायनिक द्रव्यांचा अथवा संयुगांचा आणि काही ठराविक धातूंच्या पट्ट्यांचा वापर करून वीज साठवण्याची क्षमता निर्माण केलेली असते.

बॅटरी चार्ज केली जाते तेव्हा बाहेरून पुरवलेली वीज / विद्युत प्रवाह वापरून एका विशिष्ठ प्रकारची रासायनिक अभिक्रिया होते आणि बॅटरीमध्ये ऊर्जा साठविली जाते. याउलट जेव्हा बॅटरीद्वारे एखादे विजेचे उपकरण चालवले जाते तेव्हा विरुद्ध प्रकारची रासायनिक क्रिया होते आणि बॅटरी डिस्चार्ज होते किंवा उतरते. जेवढी ऊर्जा साठवलेली असेल त्याप्रमाणात ऊर्जा वापरायला घेऊ शकतो.

ह्या प्रकाराला चार्ज आणि डिस्चार्ज सायकल असे म्हटले जाते.

साहजिकच जितक्या मोठ्या प्रमाणात वीज साठवून ठेवायची असेल तितकी मोठ्या आकाराची (आणि किमतीचीदेखील) बॅटरी वापरणे आवश्यक असते. कुठल्याही बॅटरीचा महत्वाचा भाग हा असतो की – बॅटरी पूर्णपणे निरुपयोगी होईपर्यंत किती वेळा चार्ज आणि डिस्चार्ज करता येईल. बॅटरी बनवण्याच्या तंत्रज्ञानानुसार आणि प्रकारानुसार ज्या काही चार्ज-डिस्चार्ज सायकलची संख्या शक्य असते तितकी वापरून झाली की बॅटरी निकामी तरी होते किंवा अतिशय कमी क्षमतेने काम करू लागते.

चांगल्या दर्जाच्या बॅटरीला चार्ज-डिस्चार्ज सायकल खूप जास्त असायला हव्यात.

आजकाल विविध प्रकारच्या बॅटरी उपलब्ध आहेत.

त्यामध्ये बऱ्याच काळापासून स्थिरावलेला आणि प्रचलित प्रकार म्हणजे लेड एसिड बॅटरी –

ही खूप जड आणि जाड असते, द्रवरूपात आम्ल भरलेले असते त्यामुळे जेथे बॅटरी एकाच ठिकाणी कायमस्वरूपी ठेवायची आहे फक्त तेथेच ही सोयीची होते. तुलनेने किंमत कमी आहे, परंतु हिचे आयुर्मान / चार्ज-डिस्चार्ज सायकल्स सुद्धा कमी असतात.

दुसरा अलीकडच्या काळात प्रचलित होत असलेला प्रकार म्हणजे लिथियम बॅटरी, वजनाने हलकी आणि जास्त आयुर्मान – अर्थातच महाग.

The commonly known approach to store electricity is a battery which is based on chemical reactions between metals/non-metals and acid or such liquids. During the charging process a specific chemical reaction happens and electric energy is stored in chemical form. Later when the electricity is consumed, a reverse chemical reaction occurs and battery discharges or drains.

Such a process is called as one charge-discharge cycle. After the permissible charge-discharge cycles are exhausted, the battery goes almost dead/useless and needs to be replaced.

Obviously a good battery needs to have large number of such charge-discharge cycles and it needs to have large enough the storage capacity based on usage requirements.

There are two popular battery types

Lead Acid: An old timer, heavy, contains acid in liquid form, good for stationary applications, relatively lower priced but also less number of charge-discharge cycles.

Lithum Based: Relatively new, light weight, usable on the move, costlier but also supports more charge-discharge cycles.

बॅटरीच्या क्षमतेकरीता विद्युतभार (व्होल्टेज) आणि प्रवाहक्षमता (अँपिअर-अवर ) अशी दोन परीमाणे प्रचलित आहेत.

उदाहरणार्थ : घरातील इन्व्हर्टर साठी १२ वोल्ट आणि १८० अँपिअर-अवर ची एखादी बॅटरी सामान्यतः बसविलेली पाहायला मिळेल.

सोप्या भाषेत सांगायचे तर अशी बॅटरी १२ वोल्टवर चालणाऱ्या उपकरणामधून १८० अँपिअर इतका करंट एक तासभर प्रवाहित करु शकेल.

किंवा १८ अँपिअर १० तासाकरिता

किंवा २ अँपिअर ९० तासाकरिता

आणि अश्या प्रकारे १२ x १८० = २१६० वॅट अवर = २.१६ के डब्ल्यू एच (KWH) इतकी विद्युत ऊर्जा ही बॅटरी साठवून ठेवू शकेल आणि हवी तेव्हा पुरवू शकेल.

मात्र हे असे करताना बॅटरी चे एक चार्ज आणि डिस्चार्ज सायकल संपले असे होईल.

Typically a battery is specified by its voltage and current rating as an example, a household inverter battery would be a 12 VDC 180 Amp-Hour capacity. That means it can push 180 ampere current through an electrical appliance operating at 12V for one hour, or 18 ampere for 10 hours or 2 amperes for 90 hours.

This way such a battery can store and supply 12×180 = 2160 watt-hour = 2.16 KWH of electrical energy.

अशी एक बॅटरी घेऊन आपण तिला सोलर पॅनल मध्ये दिवसा सूर्यप्रकाशात निर्माण होणाऱ्या विजेने चार्ज करूया आणि सूर्यप्रकाश नसेल तेव्हा (सकाळी, संध्याकाळी आणि रात्री ) गरजेनुसार बॅटरी मध्ये साठवलेल्या विजेचा वापर करूया.

असे गृहीत धरलेले आहे की पॅनल मध्ये निर्माण होणारी वीज आणि आपल्याला दिवसाभरामध्ये संपूर्ण २४ तासांमध्ये वापरण्यासाठी लागणाऱ्या वीजेचे प्रमाण हे एकमेकांशी साधारणपणे मिळतीजुळते आहे /असेल.

आणि अशी ही बॅटरीवर आधारित प्रणाली / सिस्टीम दररोज आपल्याला वीजपुरवठा करीत राहील. दररोज २ युनिट इतका वीजवापर असेल आपल्या बॅटरीच्या ०.७५ ते १ चार्ज डिस्चार्ज सायकल दररोज वापरल्या जातील.

Let us consider that we take such a battery and set it up to get charged by solar panels in the daytime. We consume the stored electricity during the time when sunlight is not avaialble (early morning, evening and night). It is assumed that the battery and solar panels are so selected that the solar electricity generated and electricity needed for conumption is more or less matched to each other. If the daily consumption is 2KWH then such a battery would end up in depletion of its 0.75 to 1 charge-discharge cycles.

ह्यामध्ये समस्या अशी आहे की एका वर्षाच्या वापरानंतर सुमारे २०० ते ३५० चार्ज डिस्चार्ज सायकल संपून गेलेल्या असतील, आणि जरी ५०० सायकल क्षमतेची बॅटरी (लेड ऍसिड प्रकारातली ) असली तरीदेखील दीड ते दोन वर्षांमध्ये ती जवळजवळ निकामी होऊन नवी बॅटरी बसवायची (आणि तितका म्हणजे १०००० ते १५००० रुपये इतका खर्च पुन्हा करावा लागण्याची) वेळ येईल.

The problem is – after an year of usage in this way, the battry would have lost its 200 to 350 charge-discharge cycles, and even if a battery with 500 cycles is installed (typically a good quality and moderately costly variant) it will be almost dead within 2 years. Then it needs to be replaced at a cost of about 10000 to 15000 INR.

त्याऐवजी लिथियम प्रकारची बॅटरी असेल (जी सुमारे १५००-२००० चार्ज डिस्चार्ज सायकल देऊ शकते आणि निर्माते तरीही फक्त ३ ते ४ वर्षांची वारंटी/ग्यारंटी देतात) तर ती ५ ते ६ वर्षे वापरता येईल, आणि नंतर नवी बॅटरी बसवते वेळी लेड ऍसिड च्या तुलनेत ३ पट जास्त किमतीला घ्यावी लागेल.

If instead a lithum based battery is used (which has 1500 to 2000 cycles but still a warranty of 3 to 4 years) will run for about 5 to 6 years. And then when a new battery needs to be installed, it will cost almost 3 times more as compared to a lead-acid battery.

तात्पर्य – तर दीर्घकालीन विचार केल्यास बॅटरीवर आधारित सोलर विद्युत ऊर्जा प्रणाली आर्थिक दृष्ट्या परवडणारी नाही.

Conclusion : In long term a battey based solar electric system is not financial viable.

आपल्याला इमर्जन्सी म्हणून एखाद्या उपकरणाला वीजपुरवठा करणे गरजेचे असेल तर मात्र बॅटरी वर आधारित सिस्टीम वापरणे अपरिहार्य ठरेल.

As an emergency requirement if any device needs to be always up and running then a battey based system is an unavoidable option.

तर मग ह्याला एखादा चांगला पर्याय आहे का? पुढील भागामध्ये पाहूया.

So then is there any better alternative to this? we will see in next part.

Solar Energy

सौर ऊर्जा आणि आपण – २

भाग २ – घरगुती वापराची वीज

Part 2 – Electicity for Household Use

घरात आपण वापरतो ती वीज आपल्याला वीजमंडळाच्या वीजजाळ्यातून (इलेक्ट्रिक ग्रीडमधून ) मिळते.

The electric energy that we use in our households is available to us from the electric grid of the supply company.

वीजजोडणी १ किंवा ३ फेज ची असते, साध्या वापरासाठी १ फेजचा वीजपुरवठा पुरेसा होतो, परंतु जास्त वापर करणारी उपकरणे जसे की मोठ्या क्षमतेचे पंप , यंत्रसामग्री इत्यादी साठी ३ फेज पुरवठा सोयीचा होतो .

The electric connection is either 1 phase or 3 phase, for small scale household usage single phase connection is adequate, but for large sized pumps and equipment a 3 phase supply is better and recommended.

आपण वापरतो त्या विजेचे बिल आपल्या वापराच्या युनिट नुसार वीजमंडळ दरमहा आपल्याला देते आणि त्याचा भरणा वेळेवर न केल्यास आपली विजेची जोडणी खंडीत करण्याचे अधिकार वीजमंडळास असतात.

The monthly electric bill is generated based on the units of electricity that we use, if not paid within stipulated time, the electric supply company can disconnect the electric supply to the consumer.

वीजवापर मोजण्यासाठी एक मीटर बसविलेला असतो आणि त्यावर आपल्या विजेच्या वापराची संख्या के-डब्ल्यू-एच (KWH) (सर्वसामान्यपणे युनिट असे म्हटले जाते) मध्ये सतत दाखविली जाते.

To measure the consumption of the electricity, an energy meter is installed at the premise of the consumer. On the display of this meter, the accumulated consumption of electricity is continiously displayed in KWH units.

आपल्या माहितीकरिता आणि कुतूहल म्हणून आपण आपल्या मीटर वर सतत दाखवल्या जाणाऱ्या आकड्यांचा परिचय करून घेतलेला बरा.

It is a good thing to know the location and details on the display of our own energy meter.

वेगवेगळ्या कंपन्यांचे मीटर थोड्या फार फरकाने विविध प्रकारची माहिती स्क्रीनवर एकामागून एक दाखवत राहतात – दिनांक, वेळ, आतापर्यंत झालेल्या वीजवापराची युनिटे अर्थात के-डब्ल्यू-एच (KWH)

Energy meters from various companies, with small differenece here and there, keep scrolling the information on the display – typically date, time, accumulated energy units KWH used so far till any given point of time.

आता थोडेसे विजेच्या परिमाणा-विषयी (युनिट)

Now let us understand the unit of electricity consumed

सर्व प्रकारच्या ऊर्जेचे परीमाण वॅट हे असते आणि किती वॅट ऊर्जा किती वेळासाठी वापरली ह्याचे परीमाण के-डब्ल्यू-एच (KWH) असे आहे.

All types of energies (rather power or the rate of consumption of energy) is Watt, and how much energy used for how long is often expressed as KWH units.

तर अश्या प्रकारचे १ युनिट म्हणजे नक्की किती ऊर्जा?

So how much really is a 1 KWH?

तर १०० वॅट चा एक दिवा १० तास सुरु ठेवला तर १ युनिट वीज वापरली जाते.

If we operate a 100 watt light bulb for 10 hours, it is 1000 Watt Hour or 1KWH.

किंवा १००० वॅट (१ किलोवॅट) ची इस्त्री १५ मिनिटे (एक चतुर्थांश तास) वापरली तर ०.२५ युनिट वीज वापरली जाते.

If we use an electric iron of 1000 watt capacity, for 15 minutes, then it is 1000×15/60 = 0.25 KWH units.

किंवा २००० वॅट चा पाणी तापवायचा रॉड हीटर अर्धा तास वापरला तर १ युनिट वीज वापरली जाते.

An electric rod type immersion water heater of 2000 watt if used for half an hour then 2000×0.5=1000 Watt Hour or 1 KWH units are consumed.

ह्या पद्धतीने आपण आपल्या घरातल्या विविध उपकरणांचा जितका वेळ वापर केला जातो त्यावरून विजेच्या युनिटांचा अंदाज किंवा गणित करू शकतो.

Going by this simple calculation we can determine the approximate consumption of electricity in our home on a daily or monthly basis.

वीजवापरासाठी वीजमंडळ वेगवेगळे आकार (चार्जेस) लागू करते ,जसेकी….

Electricity company charges various rates under different heads of charges as below.

स्थिर आकार – कितीही कमी अथवा जास्त वीज वापरली तरी ही ठरावीक रक्कम दरमहा बिलामध्ये घेतली जाते, सिंगल फेज साठी सध्याचा स्थिर आकार ८० ते ११० रुपये आहे.

Fixed Charges – No matter how much electricity the consumer uses in a month, this charge will always be applied in every bill. As of now this is 80 to 110 INR per month for a single phase connection.

वीज आकार – हा आकार मुख्यत्वे वीज वापरासाठीच आहे
Electricity Charges – This is the charge directly applicable for the units of electricity consumed.

वहन आकार – मंडळाच्या वीजवाहिन्यांचे जाळे वापरून आपल्याला वीज मिळते, त्यापोटी द्यावा लागणार आकार
Wheeling or Transmission Charges – This is in a way the charges for providing electricity at a location away from the point of generation, basically the transmission related charge/cost.

इंधन समायोजन आकार – इंधनाचे दर कमी किंवा जास्त होतात त्यानुसार हा आकार लावला जातो

Fuel adjustment charges – This is levied due to changes in the cost of fuel that goes into generating the electricity in the power plants.

वीज शुल्क – वीजवापराचे शुल्क

Energy Charges – Similar to electricity charges, but just a different charge head.

वीज विक्री कर – वीजविक्री करताना लावावयाचा कर
Electricity Tax on Sale – Tax as a part of electricity sales by the supply company to the consumer.

ह्यातील स्थिर आकार वगळता इतर सर्व आकार वीजवापराच्या युनिट वर अवलंबून असतात, अर्थातच जितकी युनिट जास्त वापरली जातील तितके हे सर्व आकार त्या प्रमाणात लागू होणार.

Out of the various types of charges, all charges except Fixed charges are directly proportional to the units of electricity consumed. In a way these are all variable charges and will be higher in propotion to the units consumed.

त्यातही युनिटच्या पायरीपद्धतीने दर-आकारणी केली जाते ०-१०० युनिट ३ रुपये प्रति युनिट, त्यापुढील युनिट ला १०१ -३०० युनिट मध्ये गेल्यास ६ रुपये प्रति युनिट असे चढे दर लागू होतात.

Variable charges are mostly grouped in increasing slabs of consuption, e.g. 0-100 units 3 INR per unit, 101 to 300 units are charged at 6 INR per unit.

आणि ही दर आकारणी ग्राहकाच्या टॅरीफ (वीजदरतक्ता ) नुसार बदलते, साधारणपणे MSEDCL च्या सर्वसाधारण वीज ग्राहकाला 090 /LT-I (B) Residential 1Ph हा टॅरीफ लागू असतो, परंतु असे अनेक टॅरीफ नेमून दिलेले आहेत आणि त्या त्या प्रमाणे दर आकारणी केली जाते.

This actual rates of various charges are also dependent on the tariff category assigned to the consumer. As an example, for the standard residential consumer, MSEDCL in Maharashtra applies a tariff – 090 /LT-I (B) Residential 1Ph

Solar Energy

सौर ऊर्जा आणि आपण – १

उर्जाक्षेत्राशी प्रत्यक्ष संबंध नसलेल्या जिज्ञासू नागरिकांना सौर ऊर्जा प्रत्यक्ष कशी वापरायला सुरुवात करता येईल ह्याबद्दल माहिती देणे हे या लेखमालेचे प्रयोजन आहे.

अभिप्राय आणि/किंवा प्रश्न अवश्य लिहावे.

भाग १: सौर ऊर्जेची प्राथमिक माहिती

आपल्याला सौर ऊर्जा प्रामुख्याने दोन तऱ्हेने मिळते, प्रकाश आणि उष्णता.

यापैकी उष्णतेचा उपयोग घरगुती प्रमाणावर पाणी तापवणे किंवा पदार्थ वाळवणे यासाठी केला जातो, तर मोठ्या प्रमाणात किंवा औद्योगिक स्तरावर सूर्याच्या उष्णतेपासून वाफ निर्माण करून त्यावर जनित्रे (टर्बाईन) चालवून वीजनिर्मिती करतात.

सूर्य प्रकाशाचा उपयोग थेट प्रकाश म्हणून तर होतोच, परंतु सूर्यास्तानंतर प्रकाश / ऊर्जा मिळवता यावी यासाठी विशेष योजना करावी लागते.

आपल्या घरात, कचेऱ्यांमध्ये, शेतीमध्ये किंवा कारखान्यांमध्ये विजेचा विवीध प्रकारे करता येऊ शकणारा वापर आणि त्यामुळेच निर्माण झालेले विजेचे महत्व काही वेगळे सांगायची गरज नाही.

वीज किंवा विद्युत-ऊर्जा अनेक मार्गांनी आपल्याला वापरायला सोयीची ठरते, त्यामुळे गेली कित्येक दशके पारंपारिक पद्धती वापरून वीजनिर्मिती सुरु आहे, आणि ह्या पृथ्वीवर विजेचा वापर यथेच्छ सुरु आहे.

पारंपारिक पद्धतींमध्ये कोळसा किंवा जीवाश्म इंधने (पेट्रोलियमजन्य ज्वलनशील पदार्थ) वापरून वीजनिर्मिती केली जाते आणि त्यातून निर्माण होतात – प्रदूषणकारी वायू आणि वातावरणातील प्रतिकूल बदल.

प्रदूषणाला आळा घालण्यासाठी आणि दुसऱ्या बाजूला इंधनांचे संपत चाललेले साठे व त्या अनुषंगाने वाढत चाललेल्या किंमती यावर उतारा म्हणून सौरऊर्जेचा सशक्त पर्याय पुढे येत आहे.

सूर्यप्रकाशापासून थेट वीज निर्माण करू शकणारी सौरविद्युत पॅनेल्स गेल्या बऱ्याच वर्षांपासून उपलब्ध आहेतच आणि निर्मितीप्रक्रीयेतील संशोधन व सुधारणांमुळे पॅनेलच्या किंमती मोठ्या प्रमाणावर कमी होऊन स्थिरावल्या आहेत.

आपल्या घरात वीजमंडळाने पुरविलेल्या विजेला सोलर पॅनल वापरून निर्माण केलेली वीज पर्याय ठरू शकते आणि अश्या प्रकारे सोलर पॅनेल्स बसवून आपले विजेचे बिल देखील कमी करता येऊ शकते.

ह्यासाठी सर्वसाधारणपणे तीन प्रकार उपलब्ध आहेत.

१. बॅटरीचा वापर करून
२. वीजजोडणीचा वापर करून
३. सौरविजेचा थेट वापर

आपण याबद्दलची माहीती क्रमशः घेऊया…….

The purpose of this set of articles is to provide information about how to start using solar energy, to the curious citizens who are not directly related to the energy sector.

Feedback and / or questions are anticipated.

Part 1: Basic information on solar energy

We get solar energy in two main ways, light and heat.

Most of the heat part is used for domestic water heating or drying, while on a larger / industrial scale, electricity is produced by generating steam from the heat of the sun and running turbines.

Sunlight is used as direct light, but special arrangements have to be made to be able to use the energy after sunset.

Needless to say, the ease of use of electricity in our homes, offices, farms or factories and hence the importance of electricity is already very well established.

Electricity or power-energy is convenient for us to use in many ways, so since last several decades electricity is being generated using traditional methods, and there is large scale consumption of electricity common across all countries in the world.

Traditional methods generate electricity using coal or fossil fuels (petroleum based substances) and it leads to release of polluting gases and also results in adverse impact on our climate.

A strong alternative of solar energy is emerging, to curb pollution and, on the other hand, to tackle the depleting fossil fuel reserves and their rising prices.

Solar panels that can generate electricity directly from sunlight have been available for many years, and research and improvements in the manufacturing process has led to a significant reduction in panel prices. As of now the prices are fairly stabilized.

Electricity generated using solar panels can be an alternative to the electricity supplied to our home by the power board and thus installing solar panels can also reduce electricity bills.

There are generally three types of systems available for using solar energy for electricity.

1. Battery based systems

2. Grid connected systems

3. Direct use of solar electricity

We will look at these options in subsequent articles…..

Coronicles OutOfTopic

Pulse oximeter

An informative video explains about importance of oxygen level in blood as a percentage of saturation level.

Recommended oxygen level is 94+ percent. And rather than instantaneous value the trend over a few days would be more indicative of any cause of concern.

Video duration 10+ minutes.

थोडक्यात महत्वाचे
कोरोना झालेल्या बऱ्याच पेशंटचे रक्तातले ऑक्सीजनचे प्रमाण सातत्याने कमी होत राहते आणि श्वास घ्यायला मात्र त्रास होत नाही

साध्या न्यूमोनियामध्ये श्वास घ्यायला लवकर त्रास सुरू होतो, त्यामुळे पेशंट लगेचच आपणहून डॉक्टरकडे जातो.

कोरोना मध्ये मात्र अशी काहीही लक्षणे न दिसता ऑक्‍सिजनचे प्रमाण कमी कमी होत राहते, म्हणूनच बऱ्याच केसेस मध्ये अचानक इमर्जन्सी उद्भवू शकते

यावर आपण घरच्या घरी करू शकू असा उपाय म्हणजे – साधे पल्स ऑक्सीमीटर हे यंत्र वापरून आपल्या रक्तातली ऑक्सिजनची पातळी मोजत राहणे

आता आपल्याकडे दोन पर्याय आहेत
एकतर रीतसर ऑक्सीमीटर इन्स्ट्रुमेंट घेऊन येणे किंवा काही निवडक फोन मॉडेल साठी फक्त एक ॲप इन्स्टॉल करून फोनचा कॅमेरा आणि/ किंवा एलईडी सेन्सर वापरून थोडी कमी अचुकता असलेले रीडींग घ्यायचे.

The app in the link below seems to be only for iPhone, does not show up on my phone playstore (must be due to incompatibility with my Redmi note4)

Requesting all iPhone users to try this app and be informed about oxygen levels of your own and your near and dear ones. Someone reported that Apple stopped supporting such apps.

Also there are some Samsung specific apps.

A request to readers to please report any and all who can or cannot use this or any similar app.

मी गुगल प्ले स्टोअर मध्ये काही ॲप पाहिली
माझ्या फोनला सेंसर शिवाय चालू शकेल असे ॲप सापडले नाही

So then I decided to purchase one such pulse oximeter from Bafna Surgicals near Louis wadi Thane.

It is from a brand named ChoiceMMed and costed me 2500 INR. Works on 2 pencil cell batteties and displays pulse rate per minute and oxygen level in percent.

Opinion of doctors also taken, as per them it’s good to self check anyways.

The first link of the video was shared by my school group friends and also mentioned about experience with such an instrument and about app based measurements taken.

Good to share such information in the current panic pandemic, and the instrument if available at hand can be used to help people in your locality to self check themselves.

It would be good to insist that the person must wash hands with soap before using the instrument.


Mini Weather Station (DIY)

A simple Arduino based weather station is installed outside of the window of my house in Thane, Maharashtra, India 400602.

Weatherstation Device
Weatherstation Device

Supported by the home WiFi network it keeps logging the temperature and relative humidity data to the Thingspeak platform. All / most of the components used are open-source and easily available in local electronic market or online.

And the data is logged every 2 minute thus near realtime…….

The weather data can also be viewed at the link

Temperature DegC for last 2 days

Relative Humidity % for last 2 days

So far, 2 years of data has been captured at every 2 minutes. The trend is typical and repeats every year with a few changes.

Can this data be used to conclusively confirm about global warming and climate change?

May be not.

It requires many years (5 or 10?) of data to be logged and also at various multiple locations.

So, anyone interested in installing such a weather station?

The device is about 1100 to 1300 INR for the cost of components, and may take upto 2 to 5 watt of continous power consumption and about 2MB data per day.

If anyone is keen to track the local temperature and humidity, please get in touch.

It is a small device about 4 x 4 x 2 inch PVC box and need to be installed under some kind of weather shed.

All you need to have is below.

  1. A ventilated outdoor space, it can be a balcony / terrace, but no direct sunlight and no direct rainfall at least where the device will be mounted.
  2. A continously available WiFi data network.
  3. Source of electricity to power the device.

It will be really great and interesting, if we team up for multiple such stations at various geographical locations.


Carbon Footprint

This may sound to be only a jargon. But in simple words it means the amount of carbon dioxide (and heat energy) gets released in environment due to activities of a person or of a community – either individually or as a group.

And why should one be worried about this? Short answer is – more the CO2 and/or heat released in atmosphere more will be the adverse impact on weather, surroundings, flora and fauna and even the seasons and annual cycles of rain and winter and summer.

This can be calculated or estimated to a very accurate detail but will need lots of data.

So here above is a simple calculation for typical urban or semi-rural lifestyle of current days. As of corona outbreak the human activity has significantly reduced worldwide and so is the impact on environment – expected to have reduced.

Please go through the list and verify how much is your contribution.

Comments please.