Frequently Asked Questions

Q: How efficient are solar panels? How much power can they produce per square foot?
Q: What happens if it's cloudy or rainy for several days in a row?
Q: Do I need batteries in my solar electric system?
Q: But if I don't have batteries, how will I get electricity during the night or when the sun isn't shining?
Q: What modifications would be necessary for my house to run on solar electricity?
Q: So how do you estimate the cost of a solar electric system for my home or business?
Q: What does an average solar electric system cost?
Q: What modifications would be necessary for my house to run on solar electricity?

Answers

Q: How efficient are solar panels? How much power can they produce per square foot?
A: The most commonly used solar panels have efficiencies ranging from 11%-14% and produce about 10-13 watts per square foot. New panels are on the market that reach up to 20% in efficiency; however, in general, the price per watt rises significantly with increasing panel efficiency. So, although efficiencies can reach up to 30% or more, the cost is usually prohibitive except for military or space applications. At the end of the day, panel efficiency really equates to how much power can be generated in a given amount of roof space. So, for basic planning purposes, a good rule of thumb is 12 watts per square foot.

Q: What happens if it's cloudy or rainy for several days in a row?
A: Your solar electric system would produce less electricity, but you wouldn't notice the difference inside your home. Grid-tied solar systems never "run out" of electricity. Although solar panels only produce their maximum output in full, unobstructed sunlight, they will still produce power on cloudy or rainy days - albeit much less than normal. During these times, you end up buying more power from the utility company to make up the "deficit." When we design systems we take into account weather variables and can accurately estimate monthly and annual solar electricity production.

Q: Do I need batteries in my solar electric system?
A: Batteries are only necessary if you are (a) living "off-the-grid"; or (b) living in an area with a high occurrence of power outages. Most solar electric systems in urban areas, where grid connections already exist, forgo batteries and effectively use the utility grid as a battery. Not having batteries in a system will reduce the overall cost and virtually eliminates maintenance

Q: But if I don't have batteries, how will I get electricity during the night or when the sun isn't shining?
A: If you're tied to the grid, then you simply take electricity from the utility. This happens whenever you are consuming more electricity than your solar system is producing - such as at night or during rainy weather. When the sun is shining, however, and you are producing more power than you're consuming, then the solar system will feed the excess electricity back into the grid, causing your meter to spin backwards. Each month, your utility meter may spin backwards and forwards on a daily basis, but your monthly utility bill will only show the "net" change that occurred. This is called "net metering" and it allows you to achieve a "net zero" bill by selling back the power that you use at a RETAIL rate. If you produce MORE power than you use each month, the credits will carry over for later use for up to 12 months. Afterwards, if you still have a credit leftover, the utility may pay you for the excess power you produced, but it will only be at the WHOLESALE rate which is much lower than retail.

Q: What modifications would be necessary for my house to run on solar electricity?
A: Very little, if any. Solar panels are relatively lightweight, so there are rarely any structural modifications required. Conduit and wire must be installed from the solar panels to the electrical panel. Typical installations take only 1-3 days, with only 1 hour without power.

Q: So how do you estimate the cost of a solar electric system for my home or business?
A: We start by analyzing your recent utility bills to determine how much electricity you consume per month (measured in kilowatt-hours = kWh) and on an annual basis. We then factor in specific issues that are unique to your home or business such as available roof area and shading from trees or other buildings. We'll then be able to show you the investment required to produce as much as 100%, or even as little as 10%, of your electrical power needs.

Q: What does an average solar electric system cost?
A:Most residential solar PV systems cost between $5,000-$15,000 (after rebates and incentives) which includes the cost of all materials, installation, freight, permit fees and sales tax. Solar PV systems for small businesses typically range from $10,000-$35,000 while large-scale commercial projects can range from hundreds of thousands to millions of dollars.

Q: What modifications would be necessary for my house to run on solar electricity?
A: Very little, if any. Solar panels are relatively lightweight, so there are rarely any structural modifications required. Conduit and wire must be installed from the solar panels to the electrical panel. Typical installations take only 1-3 days, with only 1 hour without power.