Links about renewable energy homes.

I’ve been spending a lot of time researching renewable energy options for our new home. Here are some of the more useful web-based resources that I’ve come across.

Published by Waldo Jaquith

Waldo Jaquith (JAKE-with) is an open government technologist who lives near Char­lottes­­ville, VA, USA. more »

16 replies on “Links about renewable energy homes.”

  1. I used to volunteer at a non-profit called Urban Options that educated the public on energy and environmental issues for their home, neighborhoods, and urban centers. Although they’re located in Michigan and their services might not be available, their info, website, and links will provide valuable.

  2. Waldo —

    If you have a site that has the proper orientation and exposure, you should consider solar collectors or shingles and selling power back to the power company. My understanding is that the cost has come down significantly, and there is company in Palo Alto that is apparently ginning up to produce collectors that are about 1/3 the price per kwhr of the competition. I don’t know that they have a local distributor, but if you’re not looking to do it right away (i.e. actually put a roof on in a year), that might be a cost-effective alternative. Analyses that I have seen suggest that the extra cost of solar-produced electricity sold back to the power company pays for itself in about 5 or 6 years — effectively a 15% return on investment.

  3. We’ve selected a site to make a passive solar structure possible, and fully intend to have an active solar component. Since we’re still figuring out how much house we can get for our budget, we don’t know if we’ll be able to have any PV arrays up front, but we’ll certainly start off with an inverter and some DC lines for major appliances. It sounds like it’ll pay to hold off on those arrays, anyhow — 2/3 cheaper arrays would be great. Decent ones seem to run about a grand for 200 watts right now, and dropping that to $350 would be pretty great.

    Net metering isn’t anything to write home about here in Virginia — neither the state nor Dominion offer any incentive to generate excess power, and Dominion sells it back to you for more than they pay you for it. In this part of the country I’m not likely to turn a profit on net metering within the lifetime of the PV arrays (between the angle of the sun and weather patterns, it’s not ideal), but maybe with a little microhydro and some small wind it might get close enough.

  4. Your prices for PV sound a little high. You don’t mention whether you will be using groundwater/surfacewater, alternative energy is the best way to assure that you have the necessities – running water. I’ve had alternative (PV) for over 10 years. It is more reliable than the grid.

    There is alot to learn but its sounds like you are on the right track – reduce your needs (siting, passive solar, efficiency), diversify your energy sources (PV, wind, hydro, wood, propane), diversify your load (DC, AC). Maybe start off more dependent on petrol, and build in alternative during the life cycle so that when a generator dies, or the grid goes down, you don’t need to replace it.

    Net metering is an unrealistic dream, more reliable energy and self sufficiency are a better goal. But beware, you will become CEO of WaldoCo – the family energy utility.

  5. Your prices for PV sound a little high.

    I hope so. I’ve been looking at some of the longer-lasting ones, where the manufacturer warrantees that they won’t degrade as quickly as others. I guess the average is 1%/year of degradation, which is a pretty significant drop in output over the life of the panel.

    You don’t mention whether you will be using groundwater/surfacewater, alternative energy is the best way to assure that you have the necessities – running water.

    We’ll be using groundwater — our water table is only ~36 feet down, so we can go ahead and have a well. BTW, for folks without backup power, it’s great to have a drilled-well bucket. That way you can have water even when you don’t have power. You’ve got to haul it up, but at least you can flush your toilets, wash your hands, and have a little to drink.

    We have about 4,300 heating degree days / year here, and a little over 1,000 cooling degree days — last year we had a spike of 920 heating degree days, but cooling degree days never exceeded 369. If we can keep our BTUs/ft2/KwH under 2.0 through high R-values and proper window / overhang construction, that’ll put us in a good position to heat with split ductless and derive a majority of our energy from active solar with an investment of about $25k in equipment.

    What I don’t know yet is whether our stream has enough vertical drop to make microhydro worthwhile, and our small wind may well be a little too small to bother with, but I’m hoping JMU’s anemometer loan program will help me with that.

  6. I have been thinking about getting (at least) a line available at the wellhead that could be connected to an inverter. Also, PTO generators. Solar is way in the future for us right now; too many other costs taking up the cashflow. (kids, graduate school, etc)

    Lisa is getting her Doctorate at ODU/SVCC at almost $500/mo. That puts a serious crimp in the budget.

    I want a geodesic dome house, have been looking at designs for over 20 years now.

  7. Were looking at purchasing a motorhome in 3-5 years*, we just starting looking at them, but the one I saw had solar panels and some other energy saving advances. Of course they aren’t very fuel efficient but we would like to make it as eco-friendly as possible. In your research, did you find anything that addresses RV/Motorhomes specifically?

    *My hubby is looking at retiring from full time work then and wants to sell everything (incl. house) and live/travel in this motorhome (*gulp*)

  8. In your research, did you find anything that addresses RV/Motorhomes specifically?

    Only that they’ve come up over and over again. It had never crossed my mind RVers would have any use for solar panels, but they obviously do — probably 10% of the websites that I’ve read about the commercial applications of PV arrays have contained some reference to or section about solar panels for RVs. So hopefully you should find a lot of information out there.

    Sounds like your husband is looking for a pretty serious change in life. But it could be a lot of fun. My wife’s retired cousins do just that, and they think the world of it, spending their time exploring the country.

  9. I wouldn’t worry about replacing a polycrystalline PV panel in your lifetime. There is a slight fall-off of output in the first few years. But my panels are 40 years old (bought them used from Uncle Sam and they are within 10% of original spec. output.

    The amorphous film PV panels have a shorter life, but that appears to be improving. There is a developing ribbon film method of silicon crystal manufacture that is set to rock the industry.

    Water at 36 ft! Of course it depends on the production capacity of the well, but you could pump nearly 2 GPM at 36ft of lift with a Shurflo DC submersible pump, and accumulate to a larger pressure tank, or tanks. The great thing about these VDC pumps – they are light, homeowner friendly (you replace the diaphragm every few years) and can be hoisted by hand, run solar direct, and if everything fails you wire them to the family generator – the car to make the water flow. The cost is similar to a standard and inefficient AC submersible. In any case, a VDC pump is the most efficient – check out Lorentz and Grundfos.

    Are you planning to run your HP compressor off of your solar/wind generating capacity? I’m wondering if you have investigated propane as a heating source – it would greatly decrease your electrical needs? All you need is low-volt control power and a squirrel-cage fan. With passive, mass, and insulation you should have modest needs.

    Hydro is the silver bullet (wish I had it). For hydro, check out the Harris Stream Engine, the Low head model LH 1000 requires a bold stream, but if you have 800 gpm and 2 meters of drop you can have nearly 500 watts continuous. That’ll charge the batteries!

  10. We haven’t looked into different types of well pumps at all, but I will look into your suggestions — thanks for that.

    We’re planning to run everything through our inverter, storing generated power in batteries, so it’ll all be AC. Our builder is exploring our best heating options, and that’ll mostly be a function of house design. If the heat flow favors wood, we’ll stick a stove in the basement. If the floor space isn’t open enough, we’ll need distributed heat, probably through split ductless. Etc. It’ll be a function of what’s best for the space more than anything else.

    We have no bold stream, I’m afraid. Ours runs year-round, though it did peter out this summer for the first time I’ve ever seen. I can’t imagine that we’ll ever get much juice out of it — there’s very little drop and, though I’m not smart enough to be able to figure out the GPM, I’m quite certain it’s a lot less than 80gpm. Since it runs stronger in the winter, when we’ll get less sun, I do think it could be a nice bonus to our battery charge, but it will never be a significant source of power for us.

  11. There are some compelling reasons to split your load – AC and DC. All inverters have an idle draw that constantly uses energy as they wait for you to switch on your load. And convertion efficiencies (DC to AC) is typically 95% for inverters. So moving more load to DC reduces generating requirements – often enough to save a few panels.

    Converting VDC to chemical energy (battery) and back out to VDC also creates loss, but not as much, and there are less electronic gizmos in the process – reliability. Having water, heat, and some lighting set up bone simple in VDC has advantages.

    I heated with wood exclusively for many years. However arriving back late during a vicious cold spell to find a house full of frozen pipes, waterfalls, and split, leaking, water valves cured me of that – I added a DC powered propane-fired forced-air heating system. There are propane catalytic wall mounted units that use

  12. I almost forgot: The developer we’re talking with has encouraged us to set up direct DC feeds for major appliances (particularly the dryer and the fridge; we intend to have a gas stove) so that we can switch those over to DC when we have enough DC generation to support them. That certainly seems to make sense to me.

  13. I think you will need to make a decision – run the appliance with DC or AC. The compressor/drum/fan motor is specific to one or the other. Sunfrost makes a very efficient refrig., DC or AC, your choice. In this case, I’d go DC for the previous reasons.

    Staber makes a DC washing machine that is very innovative – really like a vertical axis front loader (no agitator).

    I use a propane refrigerator from Servel.

  14. Oh, yeah, we’d definitely have to swap out appliances. We’ll almost certainly begin with AC appliances, and sell those in a few years to get DC ones. But it’s probably best to get the wiring in place now, so that we won’t have any obstacles to upgrading to DC-powered appliances.

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