Frequently Asked Questions

What size Solar system do I need?

This is based on your monthly utility bills, long-term energy goals, and budget. Higher electricity consumers will see a faster payback on solar. Typically we recommend that you maximize available roof space while off-setting about 110% of current electricity consumption. This will help to mitigate the impact of new “TIME OF USE” rates and will allow for consistent electricity in future years when the solar panels production degrades slightly. You should consider long-term goals such as the possibility of investing in an electric car and powering your daily commute with the sun. Note that solar companies typically quote system size in DC (kilowatts “kW”) but this gets converted to AC through the inverter equipment.

Will solar increase my property value?

Yes. According to real estate appraisers, for every $1 of electricity that you offset through solar, it will increase the value of your home by $20. This means that your home would increase in value immediately by about the total net cost of the system after rebates.

How much roof space will my system need?

A rule of thumb is that every 1,000 Watts of solar modules will require 100 sq ft of roof space. Since most systems range between 2,000W to 6,000W the roof space required will range from 200 sq ft to 600 sq ft.

Will surrounding trees be an issue?

It depends. If the array is facing south or west, then any trees to the North will not be an issue. A rule of thumb is that any obstacle will produce a shadow twice its height. You want to avoid areas that will shade the modules between 10am and 3pm. Microinverters can help deal with shading issues because , unlike typical string inverters, instead of the entire array going out, only the affected module will be impacted by shade.

How long will my solar system last?

25 Year warranty on the solar panels (i.e. solar modules). 25 years with microinverters. If you go with a string inverter, the warranty is shorter (about 10 to 12 years) but it can be extended to 25 years at a reasonable cost.

Who handles the permits and rebates?

The installer (HPM Solar)

Is any maintenance required?

No. No moving parts. It’s wise to spray the modules with a hose every couple of months or more often in dusty areas.

Can I sell excess energy back to the utility?

Yes, this is called NET METERING. It’s not ideal though. Your best bet is to properly size the system so that you use what you produce. For example, you will want to store excess energy as a credit on your utility account and consume the credits at night or on cloudy days when the solar panels are not meeting your consumption needs. NOTE: If you sell the excess electricity, the utility buys it from you at the wholesale rate even though you pay retail rate when you consume electricity from them.

Should I install a battery backup system?

Battery backup systems are becoming increasingly popular but they are still an expensive investment. Unless you want to go 100% off-grid or you expect multi-day power outages, the return on investment doesn’t pan out for most customers. Batteries are becoming more important as local utilities implement TOU (Time of Use) rates where energy becomes more expensive in the afternoon and evening when most people come home from work and run appliances and AC. In this case, batteries for “Peak shaving” might be very beneficial as a way to maximize ROI for solar.

How many kwH/year will 1Kw produce?

A good rule of thumb is that in So. California, you can safely assume that 1kW (DC) installed in a non-shaded area will produce approximately 1600kWh per year or (133 kwh per month).

What Tax incentives are currently available for solar?

Contact us and we’ll help you determine the current incentives. Currently, we are expecting the Federal Investment Tax Credit to offset 30% in 2019, 26% in 2020, 22% in 2021, 10% in 2022, and then discontinuing after that. NOTE: HPM Solar urges you to consult with your CPA or tax advisor to determine if you will qualify and benefit from the Investment Tax Credit.