Hot answers tagged

61

Installing solar should be one of the last things you do. You should first concentrate on those things that will reduce the amount of energy you will be using. "The Green Building Advisor" has a good article on The Energy Efficiency Pyramid. I believe this article will help you make some wise decisions about where to start.


33

PV panels are ~15% efficient. Hot water panels are much more, and probably much cheaper. Way more efficient to just heat the water, rather than convert to electric and then to heat. Maybe with the exception of a heat pump... $$$


26

Payoff depends on the state you live in. NJ allows you to sell your energy credits to other companies so in NJ it is about a 3-5 year payback (which is great). Other states have similar programs or offer rebates. Check out One Block Off the Grid (http://1bog.org/) if you are interested in solar panels. They have been great at getting information about ...


12

It depends on your point of view. PV cells are a gamble from a financial POV... depending on the state you're looking at and if you finance you're looking at a 5-12 year payback. The cells are supposed to last 20-25 years, but you may need to replace some equipment after 10-12. Upsides: Energy prices will probably rise. Peak energy demand drives energy ...


12

This has already been said in one answer - but I want to say it again so that it is very clear. Generating electricity from solar only to then turn around and run electric heaters for the pool is not an efficient way to go at all. Overall such system will likely be less than 10% efficient in terms of solar energy conversion. Go with a solar water heater ...


11

Smaller panels are one way to go; see this article Hail Damage and your Solar Panels: If you decide to install photovoltaic modules and worry about hail damage, there are a couple of things to consider. One of the most important concerns the size of the modules. If the region you live in is subject to frequent or serious hail storms, ...


9

Also, depending on your geographical location, you might not get enough sun every year to make it worth. That would be an issue for me for example (though I'm not from US).


9

How much energy do you need? In four months you spend $7500, so assuming you heat using natural gas, that would indicate a consumption of about 19,000 cubic meters. At 10.8 kWh per cubic meter, we're talking 200,000 kWh; in four months that's an average power requirement of 70 kW. Can the Sun help? Reasonable solar output in New York is around 5 kWh/m2 ...


8

Very late in answering this, and my computer's wireless modem is acting up, but ill try my best from my phone. Assuming only the 30% tax rebate (i.e. not including state, local, REP, etc. incentives,) the payback on PV is roughly 15 years. The good thing about it is that as electricity gets more expensive (a long-standing trend with only one significant ...


8

You need an on-grid or grid-tie nverter, and you can buy them far cheaper than you can possibly build them. In any case the power company and electricity regulator won't let you implement the circuits yourself unless you're prepared to spend thousands on certification tests, including requirements to for example shutdown within a millisecond of mains loss.


8

Entirely apart from the high cost of electric resistance heat, (that is, regardless of heat source) a 1969 house is almost certainly going to benefit from insulation upgrades and the boring best bang-for the buck stuff nobody ever thinks is "fancy enough" to go for first - caulking, weatherstripping, and generally reducing air leakage. With the advent of ...


8

You have a pretty big pool by residential standards but I still am surprised it is costing you that much... almost $2k per month! Assuming a price of $.90 / therm (average in the NY area, according to some random site I found) and the numbers on this US Energy Star page, that's more than double what you should be spending for a 1800sf pool in New York. ...


7

Scott Adams (Yes that one), recently wrote an article,'How I (almost) saved the earth' talking about his experiences with solar cells. Ultimately he concluded they weren't worth it from a ROI perspective. We have a photovoltaic system for generating electricity. That's the most visible sign of a green home, and probably the dumbest. I expect the ...


7

In some places you can lease solar. They maintain all upkeep. You pay a bit extra each month but have no upfront costs. I can only post one hyperlink, but know of three companies. They are Solar City, SunRun and Sungevity. However, as mentioned by @jay, generating your own power is the last step. First you need to calculate your usage. Then reduce. Then ...


7

What you're describing is basically what you'll find in an RV. However, it's not likely to be as useful as you might wish. The "12V" in the name of a lead-acid battery is nominal. The actual voltage might vary between 10V and 15V. Most electronics can't tolerate that kind of variation. Audio components can suffer from ground loops. Even though many devices ...


7

Allot of DC devices at home run at various voltages from 22Volts down to 5Volts. So just running a 12Volt wire is impractical because you would have to regulate the voltage up or down - Just like with 110/220Volts now. That is why you cannot find a receptacle for 12 Volts. But You can use a 5Volt receptacle :) OK- But what has that got to do with ...


6

Good and affordable are both relative to many local factors. Your best bet is to look around you and see what fuel source is abundant. You'll also want to think about how often/long that resource is present during high power use periods as you'll need to store the power for later use which can rack up the price. There are areas of Michigan that are some of ...


6

If you're in the northern hemisphere, the lower angle of the sun in the winter is probably contributing to your low numbers. (When the sun is low in the sky it passes through more atmosphere to reach the ground.) Presumably you'll do better in the summer. Also, the tilt angle of the panels should be matched to your latitude. If your panels are mounted on ...


5

Actually your AC is much more efficient than that because it is a heat pump, not a direct conversion of electrical watts in to BTU of heat moved per hour. If you know your SEER rating, you can just divide the BTU/h by SEER to get Watts. An SEER of 10 is very common so that would mean each AC needs 800 W to move 8000 BTU per hour. http://en.wikipedia.org/...


5

I looked into PV systems in San Diego a few years back. Got a quotes from 3 or 4 companies, and after rebates, the breakeven in nominal dollars was 20+ years. Total cost to zero out our electricity bill was around $23k. A few years later, there was around $6k or so of new government incentives over and above what was available before, so I went back to a ...


5

Since you have an old car battery, the cost of damaging it by overcharging isn't much ($40?) and that would only happen if it got a lot of sun over weeks. A small home solar system might have thousands of dollars of batteries, so standard practice has long been for those to always have charge controllers. For small systems the cost of a charge controller ...


5

Electric resistance heat is expensive, no way around it. Here are a couple of high-level things you can do to reduce your bill: Common sense: Stop using your fireplace (it's sucking more heat out of the house than it's adding. Free. Conservation: Turn down the heat and wear more clothes. Free. Efficiency: Improve your house's level of air sealing and ...


4

I've been following the blog from a fellow Canadian, Dennis S., who has installed solar panels on his urban home under the Ontario microFIT program, whereby the province guarantees to buy your solar-generated electricity at a generous contract price... similar to the popular initiative from Germany. Dennis blogs at greentoronto.me. He's written about the ...


4

Neither choice is perfectly accurate and specific gravity is going to vary based on temperature and the quality/purity of electrolyte in the water over the life of the battery. The fundamental change to a battery over it's life is that the internal resistance of the battery increases and therefore the same level of chemical charge will end up resulting in ...


4

In the US in most jurisdictions, house wiring of any sort still falls under the National Electric Code. It has a brief section on low voltage power distribution, AC or DC less than 50V nominal. Wiring must be at least 12 Ga copper or equivalent, with overcurrent protection. The system must be grounded. All work in a neat workmanlike manner. And a few other ...


4

You have fifty-six 240-watt modules. They each produce 240 watts under standard test conditions (STC). STC is defined as 1000 W/m^2 of irradiance, 25ºC temperature and AM1.5G spectrum. These conditions are rarely reached outdoors. If the temperature is higher or the irradiance is lower than STC, you'll get less power. You can usually only achieve 25ºC ...


4

Typical grid connected installs of solar panels on homes need a couple of items to get them to work (it's not just lets slap some panels up there and wire it into the house). Solar panels are DC (direct current), your house is AC (alternating current), so a inverter is needed to create the AC current. Also that AC current needs to be synced to the same ...


3

I'm pretty sure you don't want to substitute that fuse. First off, the original fuse was rated for 1 A, while the new one is rated for 2 A. You'll have twice the current allowed in your system before the fuse goes. Second, the power (wattage) permitted to pass through the second fuse is 67% greater than the original fuse would allow. Grainger has an ...


3

My neighbour has a solar grid and one gotcha he told me is that if any of the panel is in the shade, then the whole panel produces 0 volts. He cops shadows from my house plus a house 30+ metres away. Check your prospective panels to see if they suffer this limitation and check your roof to ensure you get constant sunlight. Another gotcha (in Australia) is ...



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