35

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... $$$


28

Passive solar design before you build On a new build, your very first stop is passive solar design. Strutting forward and designing a bad old stickhouse, and then bolting on solar as an afterthought, is wasteful. Passive solar design means engineering the building so it does not need active heating (except on rare occasion. The occasion is rare enough ...


19

This is an XY problem at the industry level. Imagine some guy says "Design me a dimmer" and you design him an excellent triac dimmer, no big. And then he goes "Cool, can you just tack on a VFD onto this thing?" Facepalm, not in any elegant or cost efficient way. So it is with solar panels. Everybody and their dog is selling 2007 tech, a solely grid-...


17

The real problem is the monkeys. The collateral damage due to flying rocks would best be dealt with by trapping and relocating the monkeys. Or, it might be helpful to use an electric (chicken wire) fence to keep the monkeys off the roof. Other deterrents might be motion activated sprinklers or ultrasonic alarms. Obviously, there is not a perfect solution, ...


17

Assuming that you are (a) on the regular electric utility grid and (b) are on the regular natural gas delivery system (i.e., don't require propane deliveries), as a general rule, natural gas heating will be most cost-effective in most parts of the US. If you are not on the regular (utility) natural gas system then electricity has some advantages. ...


13

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 ...


12

I live in a small Himalayan Village facing the same problem. But we kept our solar panel in such a place which is not accessible to kids or monkeys. The second thing I would like to mention is that if our neighboring kids don’t have that much of vision of damage of the solar panel due to stone pelting to monkeys may broke our panel - we have to make them ...


12

If you design the solar thermal correctly, then given the annual solar insolation ( higher than my location in EU by about a factor of 2) then with good insulation you can avoid heating at all. But you will need to maximize the passive solar gain - allowing the sun's energy to enter the building in winter for example. Use underfloor heating driven from the ...


10

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 ...


10

If you plan to use that collected water for drinking and cooking then you will need a proper filtration / treatment system... Ingesting diluted bird-droppings is not a good idea... So, a simple filter may not be enough, you may well need UV treatment, but you should consult the authorities for the standards in your location you are legislated to meet and ...


9

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

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 ...


7

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 ...


7

Welcome to the land of Article 220 The procedure you're describing for determining the appropriate amperage rating of subpanel and feeder is called a load calculation, and is performed using a set of rules found in Article 220 of the NEC. While most residential Article 220 calculations are performed for services, Article 220 calculation rules apply to ...


6

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 ...


5

I'm installing a 24VDC lighting circuit in my new tiny house. Aritcle 411 of the NEC describes low voltage lighting residential wiring requirements. Here are the major points: 12VDC Power Supplies (120vac to 12vdc transformer) must be 60 watts and under 24VDC Power Supplies (120vac to 24vdc transformer) must be 96 watts and under Junction box must be ...


5

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 ...


5

How big are the rocks and how far are they being thrown from? Panels are generally designed to be able to withstand small to medium sized hail... if kids are throwing rocks large enough to break panel glass at your house, I'd imagine your house would be taking a lot of damage as well. Stating the obvious, but anything obstructing the sun will reduce output ...


5

I would think a security camera that records, along with a phone call to the police, would be cheaper and easier than trying to figure this out. Along with the threat of legal action and jail time may come restitution for any damage to your panels.


5

Start with efficiency Harper's overall point about starting with an efficient envelope is dead-on; managing solar gains is going to be a huge part of it down in Texas, and you'll also need to be careful with how you apply insulation and air barriers to avoid trapping water vapor or moisture in wall or roof assemblies. The ultimate test of this is a blower ...


5

The batteries are a "buffer" Solar panel output inherently varies with a variety of factors, even when the sun is out: temperature, shading from obstacles, incidence angle, and more. As a result, any solar power system that can't count on the grid to soak up fluctuations in power output requires some other means to do the same, especially during low-output ...


5

You paid a higher cost to have an AC with the built-in breaker circuit to handle the output from a small solar system. The built-in breaker limits the size of the solar system that you can install for your house. I would look at it as a Marketing pitch. Is there some benefit to using this "solar ready" feature when I get solar installed? Or ...


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 ...


4

Could you post a simple sign that asks the well-meaning kids to not throw rocks at your roof? You would want to depict rock throwing hitting a solar panel or glass pane. I could not find a precise sign but something like these might work as inspiration:


4

OK - so you're not going to be able to stop the kids from throwing rocks at monkeys and you're not going to be able to protect the solar panels from rocks. The only solution I see is to keep the monkeys off the roof. If the monkeys will run away from water, you can get motion detecting spriklers (available at Amazon) and mount them by your solar panels. The ...


4

If you are OK with manual transfer operation, what you're after is called a "select circuit" manual transfer switch -- they're pretty readily available, for anywhere up to 12-16 circuits. Reliance and Generac both make them.


4

Because of Ohm's Law, double the voltage and your transmission losses drop to 1/4 with the same diameter of wire. Go here and punch in your voltage, actual service amperage, distance and tolerable voltage drop in percent (try different numbers here to see the effects of different size of cable). If the distance is rather far, the calc may start talking ...


4

You could just use a 12V automotive heater like this on amazon (but really any store with auto parts should have them): The benefits are: It's a tested heater that should not burn down your building (unlike a true DIY using some type of "hot box" that might even invalidate your home insurance) Don't forget to keep flammable material well away from it or ...


4

Because even when it isn't dark, there may be clouds. The amount of power you can get from solar panels depends enormously on the amount of sunlight hitting them. My rough rule-of-thumb is that light clouds reduce the power output to a tenth of the maximum, and heavy clouds reduce it to a hundredth, or less. If you only have panels pointing one way, there ...


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