I want to solar-power my house. Advice?

I live in the Boston area. I own my home, and it's a single-family house. There's a good chunk of south-facing roof.

I expect to have some $20,000 cash on hand this summer, which should be enough to mount a capacious solar system on the roof. My thinking thus far has been to install a photovoltaic system with the capacity to run all the stuff in my house (including the constantly-running stereo :-) and probably enough extra to feed into the grid.

But I have a bunch of ignorant questions. Is that the most useful and/or cost-effective thing to do? Would I get more real energy savings doing a water heater instead? (Or are there hybrid systems on the market that do both?) Is the extra expense of an inverter (if that's the right word) worthwhile or would I be better off using the excess wattage to charge batteries instead? And last but not least, should I go for it this summer, or are there likely to be technical or manufacturing breakthroughs in the next year or so that will allow me to build a much more powerful system?

Thank you for your attention.

products coming online that are so much more effective than PV panels

an inverter is a good investment, unless you plan to replace all your AC appliances, including the stereo, with DC appliances. We have three small inverters that we use when it comes to running the fridge, computer, and TV which we use when we have a power outage and go to a generator (once kept them on for over 3 weeks with no problems). You can rewire your house with DC lighting and buy DC lamps and appliances as you need them. That's what I would do.

Can't help you on the water heater.

Great you are going solar!

and don't have the variety of choice in AC. My experience being as a sailor running all the stuff in my boat off dual 12 volt batteries.

The other consideration is resale of the property. Unfortunately anything that makes the property "different" hurts the resale. If you run everything off inverters switching back to the grid will be much simpler and give the prospective buyer the feeling of comfort that comes from familiarity.

Just my .02 worth.

Our neighbors have a dual system of lighting--AC and DC. This makes sense because we live in a rural area where it is common to have power outages that last a long time. But in an urban area, using an inverter or several inverters makes sense.

Solar hot water is generally considered to have a faster payback time than PV.

to do is to see how much you can reduce you existing power load without feeling deprived and miserable. Like, keep your constantly playing music, but check to see how many instant-on electronic devices and appliances you have that are constantly sucking power for no particularly good reason. In a moderate climate like we have in central New Mexico, gadgets often use more power than heating and cooling. Also check for substandard insulation in roof, attic, perimeter foundation, etc. Wall insulation is not as important, but it still makes sense to stop energy loss and waste before you start trying to get all your energy from the sun.

Often the local utility companies will do free or low cost energy audits to find out where the energy is going. Even better, check online for the HES (Home Energy Saver) energy audit program designed by Lawrence Livermore labs in California. It's actually sort of fun to use. You click choices to describe your house--location, which side windows face, how you heat it, type of refrigerator, on and on in detail, and then the program estimates in dollars for your area how much energy each part of your current house is using.

And there's no particular reason not to have both a passive hot water system and photo-voltaic array to furnish electricity.

world. He spends his days answering questions just like the ones you have.

He's a good guy.

I'll PM you his phone number.

Look at your current electric bill. What is your average daily use? You will have to do some math to figure that all out. What is your electricity used for? Electric water heater? Electric Heating? Do you have natural gas?

Most energy usage is for heating/cooling and for water heating.

Lets focus first on solar panels. $22,000 will buy you a 3.1 KW system (but that includes some rebates - hopefully you have some for your state). This will be about 18 170v solar panels.This means, under perfect conditions, for each hour the sun hits your panels, you generate 3.1 kw. So if you have sun on your roof for 3 hours, you generate 9.3 kw. Compare this with your daily usage.

Solar water heaters costs under $5k which could/is a good investment. Much of your water sits in the tank not being used. With solar water heating, the energy is not being used to heat the water just to sit and not being used.

Another thing is solar air heating. There are ways, much like solar water heating, to heat the air and have that heated air enter your home for heating.

I get Home Power magazine and do research on the internet. I personally have not done anything yet - I am still studying...

Also, look into reducing you energy consumption...

http://www.dsireusa.org/library/includes/map2.cfm?CurrentPageID=1&State=MA&RE=1&EE=1

You only have to pay about 1/2 the cost. In my state I would get $12,000.00 in direct tax breaks if I put proper solar on my roof. Which I am planning to do. Then I will also charge my new plug in prius with it. never have to visit a gas station again. Also, the power I don't use goes back into the grid and the power company sends me checks, imagine that!!!!

- Subscribe to Home Power magazine and its associated web site
- Grid tied is the way to go in the city
- Discount any installer claims by 20% or more, esp when it comes to payback.

Add up your electrical demand and first see how you could reduce it (Energy Star appliances, etc.).

Seriously look at a grid-tied PV system (rather than an off-grid system). You don't have to buy and maintain batteries and you can use all your current AC appliances...and...you can afford a lot more PV modules with a GT system than a OG system.

Depending on your desires, you could install both a solar hot water (~$5k installed) and a ~2 kW grid-tied PV system (~$16k) for that would provide you with a minimum of 6 kWh and 60% of your hot water per day in the Boston area in winter (and a lot more in the summer).

Best of luck!

Also - look into evacuated tube hot water heaters - they perform much better in cold weather than flat plate systems...

As an engineer, I specified a bunch of solar (hot water) systems back in the eighties. Because the sun can be very damaging, I doubt that any of the systems lasted long enough to collect the energy that was required to make the system. Few man-made items placed directly in the sun are free from the eventual breakdown from that sun. I think and hope that modern photovoltaics may be a little better...look into it.

For heating and cooling I would recommend a geothermal heat pump system. Essentially this is an indirect form of solar heat. The earth around your home collects and banks the heat in the summer when you don't need it. During the winter, a relatively small amount of electricity (maybe from the photovoltaics) collects that heat and pumps up that heat to a usable form.

There are many advantages, the heat is banked when it is available and there are no collectors placed directly in the sun. the "pay-back", i.e. the time needed to save enough energy money to pay off the system, is much better than those systems placed directly in the sun.

I have investigated geothermal. For geothermal, they have to place pipes either vertical or horizontal and are used as 'collectors'. So you have to have room on your lot and be able to place 60 foot pipes into the earth...

http://solarhouse.com/

The Compaan's home in Toledo: http://home.earthlink.net/~alcompaan/

The Watson's home in Boston: http://256.com/solar/ so they cover local grants, laws, etc.

...the hot water will be a better bang for the buck, and is a good project to cut your teeth on. The experience you get on the general task of dealing with contractors, researching, etc, will make your future PV endeavor run much more smoothly and on budget.

but we use propane for the fridge.

I'm not sure i'd recommend water for Boston. I understand that it's the biggest kwh chunk you can pull out, if you have a lot of hot water demand.

But I think straight EV has many benefits. Panels + inverter are dry, durable, and yes more fun.

I think the trick to going budget solar EV is to accept that if it has a compressor or a heating element, it ain't gonna run.

Cut your electricity use by 75%, then re-think what size system you need....

Best bang for buck is better insulation, cf lights, etc. No matter what your second/third moves are, making your house more efficient first will make your later efforts easier/cheaper.

Next, solar water heating is more effective than solar PV. However, heating enough water for your daily use won't take your entire roof.

At that point, your desires will have you choosing between a large PV array that (maybe) feeds into a grid, or a smaller PV array with a battery backup array. Do you want to pull in as much solar energy as possible, or do you want some backup power to keep essential items running during power outages?