Editor's Note: These notes came out of the July, 2002 SolarFest conference/folk festival in Vermont, where I attended several workshops. Rather than try to convert it into an article, I present my notes as the most useful way that homeowners and business owners can extract information and begin their own journey toward energy independence. While many of the examples cited are Vermont—related, the information is applicable anywhere (though the resources are primarily for customers in the U.S.). We put in a solar hot water system on our house some months before the conference; I think I'd have been a much better informed consumer if I'd attended last year's SolarFest first. Note: Shel Horowitz's book, Principled Profit: Marketing That Puts People First, contains a great deal of other information about the interplay of marketing and social change, and ways to move a business toward both environmental and economic sustainablity.
PHOTOVOLTAICS (PV)--panels that generate electricity directly from the sun JEFF WOLFE, Global Resource Options Don't think of PV as competing with the power company's subsidized electricity. Think of it as an annuity that beats the stock market and regular annuities, that provides maybe 6%. Design for energy efficiency, for major savings. PV is, only part of a solution. 9% of Vermont's energy is used to heat water. Vermont Yankee generates 33%. If we get every house in Vermont on solar hot water, we'd have 75% of its output. $6500 materials for 1 KW (kilowatt) panel, no state sales tax (in Vermont). = 3 KW per day, average house uses 20 KWH (kilowatt-hours) per day. Without electric dryer, stove, etc., about 8 KWH. So to completely do a house, 3 KW panels We really need national net metering (where utilities have to buy back surplus power from consumer/generators). Common Misconceptions
GlobalResiource Options sells 3'x6' PV panels, 120 watts per panel for
Solar strips-have 20 yr warranty when installed on galvanized aluminum roof--Unisolar Jeff: on-grid, batteryless is more efficeint, cheaper, simpler than battery systems. Use the grid as your storage battery, send it back to the grid when you make more than use, pull it in when you use more than you make. $6,000 partial load, full capacity up to $30,000 depending on how conserving your home is. PV is the cheapest electricity (discounting subsidies). PAUL SCHECKEL - writing book for Chelsea Green (my publisher) on energy conservation, energy auditor, lives off grid. All these systems affect the comfort and longevity of a home.
Average homeowner uses 30 KWH/day. I use 3 KWH and have all the modern conveniences lower consumption lower cost, lower resource consumption, independence, security, and choice
US uses 25% of world's energy--98 quads (quadrillion BTUs--15 zeroes-out of about 400 quads worldwide). We waste 58%--surely we can do better than that! Efficiency is taking advantage of technology to do the same thing better, e.g., reduce power demand by 75% by replacing a standard light bulb with a compact fluorescent bulb. Read your electric meter regularly and know what you're using. Buy a digital meter for $100. Old refrigerators--more than 10 years--probably worth replacing. Meter the old one, do the math. Wattage is an average. The sticker may not reflect true usage. Phantom loads--energy drain from instant warm-up appliances. Plug them into power strips and turn off the power strip. Saves 6 watts for TV/VCR, 6 watts for microwave--power strip pays for itself in a month. Set hot water for 100, average hot shower is 104. Factory typically sets at 140. Dishwasher will boost the temperature of the 10 gallons it uses instead of your whole tank. Low-flow showerhead with dribble switch--$5, these things are cheap. Water heater blanket--$15 will save about $40/year I have found no good reason not to wrap a heater even if it's insulated--but keep the pressure relief valve free! Don't do if it's in too wet an environment, can have condensation problems. Don't use if your cats and dogs will tear up the jacket. Don't cover if it voids your warranty. Pipe wrap--do the hot pipes, not the cold ones (unless freezing pipes would be a problem--then wrap both).
Ductwork can be a major energy thief. Tape all the seams with mastic and insulate around the ducts--have a contractor do it. Test for leakage (contractor) Don't over-size a space heater Old-style fireplaces pull hundreds of cubic feet of heated air into the chimney; they are net energy losers. Modern fireplaces, fire behind glass door, takes combustion air from outside, fan circulates air around the firebox, maximum efficiency Venting. Don't use atmospheric venting (directly at heater source) in a new, tight house; carbon monoxide will stay in your house. Use sealed combustion for tight houses. Programmable thermostats can save lots of energy by running your heat or air conditioning only when you're typically home. Turn heat back 1 degree = 3% savings May be hard to locate the lowest energy products, some are only available to the trade, or for low-income housing. The most energy-efficient fridge right now is a Maytag MTV 1956. Don't buy what's on sale, Read the Energy Guide label (FTC required) and know what you need. House shell air infiltration: chimney chases (where it penetrates the ceiling, chimney dampers, windows and doors Sealing windows with expanding foam or caulk is usually much more economical than replacing your windows. Read the Energy Guide label Cellulose can blow into places other insulation can't reach. When evaluating windows, look at U factor--low numbers are good, R factor or solar heat gain coefficient (for a sunroom, anyway), higher is better Investigate fuel switching. Propane is more expensive than heating oil AND generates fewer BTUs Electricity (on grid) is most costly fuel b/c power plant and transmission is only 1/3 efficient His website: https://www.nrgrev.com/ JOHN WITTERSDORF - HOME WIND POWER SYSTEMS Do you have wind? Indications may be deceiving. You want a *steady* wind, not gusts, the tree should lean to one direction and stays there. If you have poor wind, investing in a wind turbine is a waste of money. Recommended: 8 mph average wind speed. That's actually fairly high., I live on a mountain top, totally exposed, and I have an average speed of 5-1/2. There are a lot of days I look at the wind turbine and get really annoyed at where I live. The wind is behind me and I'm in this sheltered pocket. Look at the immediate surroundings and also off into the distance 20 or 30 miles to see what would affect the channeling. Vermont: Champlain Valley average 10-12, moderate wind site. Better sites are on the ridge tops, the higher the elevation the better. Searsburg wind farm is around 3500 feet up. Dependable, maintenance-free wind turbine does not exist right now. You don't want to have to take it down every 3-6 months and repair it. Home systems: 1 KW or 10 KW. 1 KW in an average site generates about 180 KWH/month. If you're using 100 KWH, you're doing well. If you're using 1000, look at efficiency first. Typical hone uses 500 KWH/month. Range from 300-1000. 10 KW is sizeable, needs heavy trucks. 1 KW is almost backpackable. The turbine itself weights about 55 pounds. For the small systems, the tower is normally installed with screw-in anchors, no concrete. Or you can anchor it to a rock. If those fail, concrete, but about 90% of the time we can get one of those methods to work. It can be put up easily and taken down easily; we're having zero impact on the environment, not even messing up the grass very much. Unlike PVs, off-grid systems (not connected to the utility company power network) are easier than on-grid. The turbine pus out 24 volt DC power and it goes right into your battery bank. On the grid, you have to convert 24 volt DC to AC. They don't make a direct inverter for it. Turbine and tower: $4000, + $5000 for inverter system. 10 KW: $30,000 Whisper series has problems with blades breaking, control boxes breaking. The Bergey is much more reliable, (that's what he sells). They have a really good website that will keep you busy for hours. maintenance schedule 1KW: every 7-10 years, repack the main bearing, check for loose nuts and bolts. After 20 years, visually check the fiberglass blades and make sure they haven't softened enough to hit the tower. Minimum distance from house: 1.1 x height of tower, though I've never heard of one falling over. They collapse straight down. They can be mounted on a building, preferably not one you sleep in. There is vibration, there is sound. Always have a shut off switch. It's preferable to have it away from a building. Buildings can cause turbulence. When installing a system in towns with zoning, we try to be really careful because it's always the first one they've seen and we want to set the precedent. There's nothing about a wind turbine that affects our environment (other than aesthetics). I feel wind turbines are beautiful but there are a lot of people that don't agree with me. We can do a formal site study, measuring the wind. I can judge by experience, but the site study costs half as much as the system because it requires a tower. I've been trying to set up equipment to rent, but my budget is tight. MICRO-HYDRO
High-head or low-head, high-flow I have 200' of elevation drop from the start of my pipe to the turbine (1400' long). That creates 90 psi (pounds per square inch) and I'm only using 18 gallons a minute x 2 turbines. Head x flow = power. If you have a lot of either one, you can make power. If you have neither, don't bother. RON MACLEOD
Dave: 500 watts = 12KWH/day Ron: Hydro is pretty much constant, but also a pain in the neck. The pipe pulls a lot of trash, sticks, leaves. But it's the closest thing you'll find to constant power (in renewables). Dave: I have 3 KW of solar electric and a 300 watt microhydro turbine. Over a year, they produce the same amount of power. The PV would cost 15-20K. The turbine: $1200. I've been involved in dozens of microhydro projects and each one is different. I've got a spring-fed pond on a hillside, it's like a big battery. When I need the hydro, I'll open it up, when it's sunny, I'll close it down. But October to April I run it all the time. The pipe is buried 4 feet down; my drinking water pipe is deeper because I shut it off much of the time. But it does need to be insulated (freeze proof). You can mulch it with straw, with snow. The nozzles are only 1/2 inch. A snail will clog it up. Total system cost: $3000, not counting digging the pond, which had other purposes. Ron: For all intents and purposes, you have no power from a river flowing by your property. People have tried water wheels on pontoons, propellers in the river. You can tow a turbine behind a sailboat to charge batteries, but it's unprotected against rocks, etc. During World War II, parachutists carried tiny Pelton wheels. If they came into a city where the water still had pressure, they could charge their batteries. Dave's pond was $2-3000. His systems need 15-20 feet of head on up to 200 feet. Ron: Low-head--2 feet and up. I bring in a tiny turbine, tiny little thing that costs $ 9000. But we can build them out of steel and iron instead of stainless, with 5 feet of head, for $940 + 60 for the controller. 700 watts on 5 feet of head for $2500, plus generator and controller (total ~$3600). You can live pretty well on 200 watts, really well on 500 watts, you can handle up to 10 KW (10,000 watts) on peak loads, with the right inverter. A client wanted a top-of-the-line system, 11 KW constant power, you don't even notice you're off the grid when running electric range and hot water, soup to nuts--$18,000 plus labor (VERY site-specific), 25,000 all together for this former mill site. Dave: The longer the distance, the larger the pipe has to be, and pipe is an expensive part. Ron: wire prices have come way down--very efficient modern electronics. We use much higher voltage and lose much less in transmission. On low-head, the penstocks are big. If you own a former mill site--they didn't have penstocks, they used an open canal. You have to get the water away from the stream bed and put it back in 30 feet later underground. Use the natural contours of the canal. I tell people use as little head as you can, your penstock is shorter, fewer environmental problems. Your goals are different from big hydro. A good steel water wheel is more efficient than any turbine. But you may need a very big wheel., 6-8 feet in diameter, very light sheet metal with pop rivets so it never rots, then find the best speed increaser you can. You have to select a very low speed alternator. You can't do net metering (selling power to utility companies) because the utilities know how effective it is (and have blocked it). The federal government doesn't even consider hydro to be renewable. Dave: Do you own both sides of the stream, is there brook trout? How non-interventive can you be? You don't want to dry up the entire flow. Ron: Don't be stupid about it--you're making a big investment, get the legalities in order. Use weirs that only go part-way across the stream, not dams all the way across. For low-head systems, you need enough standing water so air won't vortex. In some circumstances, you can find two feet of standing water behind a ledge! Do your homework, know what will hurt the environment and what won't. If your stream is already filled with cow flop, no one will care what you do to it--but try a class A fishing stream... Dave: Beavers won't bother you if you take less than 10% of the stream Ron: If you hook to the grid, the Federal Energy Resources Comission will manage you to the nth. You have to meet the same standards as a utility. The FERC can fine you 10K per day. RESOURCES ON THE WEB
Note: Shel Horowitz's book, Principled Profit: Marketing That Puts People First, contains a great deal of other information about the interplay of marketing and social change, and ways to move a business toward both environmental and economic sustainablity. |
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