More and more homeowners are turning to rooftop solar as energy bills and power outages are on the rise. Whether your goals are cost savings, more independence from the centralized energy grid, carbon emissions mitigation, or all of the above, it is a good idea to have an estimate of what your home’s solar project would look like before you begin gathering quotes.
This is where the website SolarReviews can help, providing both customer testimonials on installers, and a handy Solar Calculator to estimate system size, production, cost, and savings. Based on a few parameters like your zip code, average monthly bill, electric utility company, roof direction and pitch, and desired percent of energy covered by solar, the calculator will generate a suggested system size and project savings over the life of the system.
“It’s a truly open calculator,” Andy Sendy, SolarReviews CEO told pv magazine. “We educate consumers so they can’t get ripped off.” Sendy said there is no reason interested homeowners shouldn’t have full access to the mathematics of solar.
The Solar Calculator is regularly updated with new assumptions based on the ever-shifting electric rates and available incentives and programs in your utility’s territory.
SolarReviews partners with Genability, which actively feeds the latest utility rate and net metering structures into the calculator for up-to-date accuracy. It also integrates energy usage profile data from the Energy Information Administration to estimate building energy use based on different climactic zones across the nation.
“This is the greatest effort that any website has gone through to provide a fully accurate estimating tool which isn’t behind any paywall or registration wall,” said Sendy.
Once you’ve entered the basic information in the calculator, a wealth of information is provided. It will suggest the number of panels and system capacity needed, the expected payback period, 25-year net savings, and list all the federal, state and local incentives you can take advantage of. It will also provide advanced metrics like net present value and the internal rate of return.
After calculation, there are sliders available to tweak the figures for accuracy. You can play with the shading, the inflation of utility electricity electric prices over time, the discount rate, loan financing rates, and choose between median pricing or a customized quote price.
For those interested in battery energy storage, you can select a quote sized to your specifications. The calculator allows users to select a no-battery option, an option that sizes the battery to store surplus energy stored during the day, one that sizes the batteries to cover overnight electricity usage over a typical day, or the largest option, which allows for running key appliances for a given amount of time during a grid failure.
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You can plan all you want, but if the utility only allows 115% of the previous electrical use in solar, but the home could hold 200% in solar, you are at the mercy of the Fat Cat utility companies with CEOs making in excess of 100 million dollars a year. If you use the calculator, include batteries so you can go off grid with the whole roof top system whenever you want to or be connected to the grid whenever you want to with some of it, but not all of it, based on utility restrictions on size of the connected panel system.
Not exactly true in CA with SCE. You just need to fill out a special justification form and they will approve it. I have had 2 locations with solar installed way higher than the bill required. 4/5 installers said I could not do it. Reality is they did not know about the justification form or too lazy to fill it out. My justification was that I planned on buying 2 electric cars and will need the extra capacity.
Pacific Gas and Electric (PG&E) would not like my application because I replaced their Natural Gas with Electric heat. They want verification of “additional” electrical loads rather than replacing their cash cow Natural Gas sales. California mandates replacing all-natural gas appliances, heaters and hot water heaters with inductive stoves or heat exchanger heating and hot water will require more electrical energy that could be provided by rooftop solar during the daylight hours but at night, the utility would have to fire up the natural gas power plants and with NEM-2.0 in effect, the utility would lose lots of money in the deal. Since I do not plan to buy an electric car during the next 10 years, there is no additional energy requirement. Only replacement energy that cuts PG&E out of selling me their expensive Natural Gas.
Good day Sir i plan to install grid solar system in my residence at cagayan de oro city, How mucj the computation my monthly electric bill 3500.00 pesos waiting your reply
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