[Screwdriva]

Greetings All,

When I recently shared that I (and a few others on TBHP) had installed a 2 Kilowatt Wind/ Solar hybrid power plant on the roof of my house in the outskirts of Mumbai back in 2006, I was asked to start a thread on this topic.

It dawned on me that many of us haven't considered the possibility never paying for power again. To be honest, the obstacles faced 10 years ago may have put off many people today. But easy availability, significantly lower cost and excellent reliability have now made ownership of a renewable energy micro power plant on your home VERY easy.

Here are some facts:

1) Cost - Around 3 Lacs all inclusive for 2 KW of solar and an optional small wind turbine for those cloudy, windy monsoon days (not required but highly recommended). That's it. After 6-7 years, you will need to pay for new batteries and service the wind turbine, but that's a marginal cost relative to the entire system.

2) Appliances Powered - TVs, 100% of lighting, fans, air coolers, refrigerator, and all other miscellaneous appliances. Only AC and large capacity heaters cannot be powered by this size of a system and require much more investment.

3) Benefits - You never have to pay for any power consumption again. The solar panels last for 25 years and the wind turbine needs service every 7-10 years. Your batteries (that store the power) can be replaced every 5-6 years (my batteries lasted 7 years).

Now here's the real attractive benefit of adopting a grid free existence, powered solely by the wind and the sun - You can charge your Reva or electric bike using this same system. Theoretically, you never have to pay for fuel to drive again!

Ofcourse, you will still need to pay the power company if you want to use Air conditioners. And you can't install this if you live in an apartment complex (which is many of us). BUT, if you do have the good fortune of living in a structure with a small number of occupants, this can change your life forever.

I'm happy to answer questions on this subject. I hope others who have embraced a grid free existence will also chime in.

[avisidhu]

Great, thanks for starting this thread Screwdriva! Some pics of the setup would be nice. I've heard about govt subsidies if we intend such an endeavor, did you avail of any such benefits?

At a global level too India has given commitments to significantly enhance solar power and pledged billions of dollars for the same. I'm sure some of it would be directed at individual home owners, which should sweeten the deal further.

It would be really great to have the perspective of those having such setup or those who tried having one.

[honeybee]

Screwdiva, any more details on what type of batteries are used? How many appliances can be powered at the same time? Any smaller capacity systems which cost less and can be used for specific uses such as corridor or passage or staircase lighting?

And would I be able to see your setup in person? Drop me a PM if you wish.

[Screwdriva]

Originally Posted by avisidhu

Some pics of the setup would be nice.I've heard about govt subsidies if we intend such an endeavor, did you avail of any such benefits?

Will get you some pictures when I'm in Bombay next.

When I decided to power my home myself, there were no subsidies as most government officials didn't know how to spell "renewable", Narendra Modi was under investigation and there were near zero suppliers in the marketplace. I bore the added cost (compared to prices today), sourced a supplier and educated myself on all the components available in India. The result of this exercise has been 10 years of reliable electricity, free of the government. More on this below.

Originally Posted by honeybee

Screwdiva, any more details on what type of batteries are used? How many appliances can be powered at the same time? Any smaller capacity systems which cost less and can be used for specific uses such as corridor or passage or staircase lighting?

I used Luminous tube type batteries with a 4 year warranty. They worked for 7 years and we replaced them as a precaution as we got a good trade in offer. These were great 10 years ago. I'm assuming more options with longer life are available today.

The number appliances that can be powered depend on the capacity of the battery bank. I have run my fridge, 10 lights, 3 fans, a TV and small electronic appliances (laptop, dvd player etc.) on a recurrent basis with plenty of spare capacity as the system is charged when the sun/ wind returns the next day. I've even run a small water pump.

I would not recommend a cheaper system than 3 lakhs as you will not be able to charge your batteries with less than 2000 Watts of high efficiency solar panels or without the help of a micro wind turbine on rainy, overcast days. Think of the system as a large inverter with inputs from the sun and wind. Without enough means to capture the power from nature, your system will underperform and you will not be able to charge an electric vehicle.

While I realize that 3 lakhs is the cost of a Nano, a car will lose most of the value in a few years whereas well made solar panels last for at least 25 years. The economics are extremely favorable over the long run if you have the funds and own your home. There is no better feeling than powering your own home independent of the government and all my neighbors have since copied our system in the years since

[Mortis]

Awesome info. Our society is hopefully planning to install some solar panels on the terrace soon so we might see lower bills in a while. I might even install a few panels on the ledges outside my window if feasible. The building has an unobstructed view of the sea so we get good sunlight for atleast an extra hour during sunset compared to the interiors.
Do you happen to know the cost of solar panels that tilt to always face the sun ? Around how much extra would those systems add in India ?
The mini wind turbines is a good idea since we get good breeze also. Do yoy have a link for one of those as well ?

[Screwdriva]

Bear in mind that it's not just a matter of adding panels. You're essentially building a power plant, so it requires the involvement of a specialist and a local electrician, along with the relevant components.

Here is the US wind turbine manufacturer I use:

http://www.windenergy.com/markets/off-grid-residential

It is ultra critical to choose the best components for your power plant. TATA BP SOLAR makes excellent high end panels, which should ALWAYS be facing the Southern direction.

For wind, Southwest makes excellent micro wind turbines. I would avoid Indian brand/ sourced components entirely.

[maddy42]

Originally Posted by Screwdriva

Here is the US wind turbine manufacturer I use:

http://www.windenergy.com/markets/off-grid-residential

It is ultra critical to choose the best components for your power plant. TATA BP SOLAR makes excellent high end panels, which should ALWAYS be facing the Southern direction.

For wind, Southwest makes excellent micro wind turbines. I would avoid Indian brand/ sourced components entirely.

I have a couple of queries i hope you could help answer:

1) Does your system provide power to the grid? If yes does it still work in power cuts and how to ensure your system doesn't send power back when probable maintenance is going on?
2) When measuring the size of the system, what helped come to the 2kw number?
3) Do you use the battery stored power primarily and rely on the grid only for excessive consumption?
4) Did you import the wind turbine or used a dealer based in india? Also what was the cost of that?

I believe there are softwares to track your daily production. Have you tried any of those? With all this info you can run a consultancy service as there are many out there interested in a system but do not know where to start.

Maddy

[Screwdriva]

Originally Posted by maddy42

Does your system provide power to the grid? If yes does it still work in power cuts and how to ensure your system doesn't send power back when probable maintenance is going on?

India does not have a smart grid. Therefore, it is not possible for IN systems to route excess power back to the grid. This does exist in Western countries and allow for renewable energy systems to earn income for owners by selling back power during the day.

2) When measuring the size of the system, what helped come to the 2kw number?

For me, it was a combination of affordability and demand. I could have paid for a 3 KW system but I would not have been able to power much more that what was needed i.e. the gain in power was not worth it. The next step was a system capable of powering air-conditioning, but that was an extra 5X what I spent at the time.

3) Do you use the battery stored power primarily and rely on the grid only for excessive consumption?

Yes, I only use the grid for occasional AC use. As such, my monthly bill rarely exceeds the mandatory minimum charge.

4) Did you import the wind turbine or used a dealer based in india? Also what was the cost of that?

Southwest wind turbines have official IN distributors and the cost is around a lakh. The biggest challenge is finding a supplier that offer a full installation service with a iron clad guarantee for parts and labor.

With all this info you can run a consultancy service as there are many out there interested in a system but do not know where to start.

God has been good to us - I am happy to share what I taught myself to help anyone interested in living off the grid and free of fossil fuel consumption. Renewable power can be attained by anyone- it requires only the will to learn, a long term time horizon to get the return your investment and the courage to embrace a new way of thinking...Oh...and your own roof space

[hangover]

This article is useful.

Could you please tell us what voltage you use? Is it 12v or higher like 24 or 48?

Did you replace your regular fridge with an inverter type model? These don't need an initial surge of 1300-1500 W at compressor start up against a steady state consumption of of 300 W or so.

The panels themselves - are they robust enough to clean dust and bird droppings by just a gentle cloth wipe down? Or say with a long handled thin rubber wedge (like the one used to clean car windshields)? Any chance of electrocution at its power output location?

I'm assuming you don't drain the batteries below 50% of full charge. If you use power all night then will the batteries get recharged fully by day? Because these are used 24 X 7? Most invertors are used only when you don't receive municipality power.

Please let us know the cost of replacing the full set of batteries every 6-7 years. Say around 60-70k?

Do you get power measurement meters in India? I haven't seen any which the public could buy. The reason I ask is if one installs this for a multi tenant building then the cost of maintenance and eventual replacement could be shared based on consumption.

[avingodb]

Useful thread; just to add that the national solar mission has been around for a decade now and is being expanded rapidly in the last five years. As far as I know, there are district level offices to take it forward.

Indian commitment at Paris COP21 of Climate Change dialogue has been to make 20% of electricity by 2025 (or 30 may be) from renewables. Solar is going to play a big role in this. Plus technological advances has made solar cheaper and more durable requiring less frequent changes. So it should be easier and cost effective now.

[GTO]

Just wanted to add that Sukam offers comprehensive solar solutions for home & commercial use - link. Here's their residential page with a ton of information.

Tata also has home products - link.

Great thread, Screwdriva . Thanks for sharing!

[vagabond128]

Thank you Screwdriva, Interesting solution.

I was thinking if I am paying Rs.1500 per month as electricity bill. It would take me more than 16 years to recover my cost. If I factor in other costs like, maintenance, replacements and interest loss, recovery period would increase further.

Isn't that costly? Am I missing something in my calculcations?

[aamateen46]

Excellent thread Screwdriva! Thanks for sharing.
I feel that awareness of this new way of living is the need of the hour. Only then will the demand increase and will result in increase in supply and easy availability of the overall infrastructure.
This will then pave way for large-scale adoption thereby reaping its huge benefits for our country as a whole!

Educating all with the information given in this thread is indeed a very helpful gesture towards the right direction.

[explorer09]

For residential use, Solar hasn't yet reached grid parity in India. So yes, the payback period is very high so you should only go for it for the satisfaction of doing something for the environment.

Solar makes perfect sense for commercial/industrial units though even at today's prices at least in most states in India.

[cooldude1988765]

Originally Posted by vagabond128

Thank you Screwdriva, Interesting solution.

I was thinking if I am paying Rs.1500 per month as electricity bill. It would take me more than 16 years to recover my cost. If I factor in other costs like, maintenance, replacements and interest loss, recovery period would increase further.

Isn't that costly? Am I missing something in my calculcations?

From what I understand, a huge part of installing your own solar roof top panels is the cost of batteries.

Telangana state has a net metering option where your excess power produced is sold to the discom. This allows you to do away with the batteries completely.

For example if you produce 200 units of solar power and consume 300 units totally every month you would only pay for the difference that is 100 units.
What I assume is there will be a huge difference in the bill amount owing to the slab based consumption charges.

Below is an excerpt from the Telangana state solar power policy.

An acquaintance lives in a Solar Apartment Complex. His power bill is usually in the Rs.50-100 range every month and around 700-800 in the summer months in spite of using 3 ACs.

The Government of Telangana is committed to promotion of solar rooftop systems on
public buildings, domestic, commercial and industrial establishments.
All incentives provided by the GOI/MNRE under the NSM or other schemes and
incentives provided by state government from time to time shall be extended to grid
connected SRPs as well as off grid SRPs.
The following additional support shall be available to grid connected SRPs as per
the capacity limit as defined by MNRE from time to time.
The consumers are free to choose either net or gross meter option for sale of power to the
DISCOMs under this policy. The tariff applicable for units generated under gross
metering at 11 KV and below would be average cost of service of the DISCOM as
determined by TSERC. The tariff applicable for units under net metering would be
average pooled power purchase cost. Projects under both gross and net metering would
be subject to monthly billing and settlement.
No distribution losses/charges shall be applicable for SRPs.
Consumer installing grid connected SRPs shall apply online with the respective
TSDISCOM either on website/through designated customer service centres. All
applications shall be processed and feasibility issued by the respective DISCOM. Such
applications will be processed within 21 days from the date of application failing which
it will be deemed to have been approved.
The above facility of gross and net metering would be extended to SRPs for a
period of 25 years. The project size at a single location would be subject to technical
constraints. The modalities of implementing the above policy directives for SRPs,
including metering, billing, settlement, payment(s) and technical aspects etc. would be
made available on the TSSPDCL /TSNPDCL website.

For those intersted in the whole policy here is the link.