Solar Facts: what is solar energy and what are the basics you need to know.

What is a kilowatt (kWh)?

A kilowatt hour (kWh) is 1kW of power being used continuously for 1 hour. As the name suggests a kilowatt is 1,000 watts. So one-kilowatt hour is 1,000 watts of electricity being used continuously for an hour.

Kilowatt-hour is the unit of measure used by utility companies for billing electricity consumption. Your electric rate multiplied by your usage in kWh plus any other service charges becomes your monthly bill.

What is a megawatt hour (mWh)?

A megawatt hour (mWh) is one megawatt of power being used continuously for one hour. A megawatt hour (mWh) is equal to 1,000kWh. Your solar systems power output measured over several years may be in mWh but annual and daily solar production numbers are usually measured in kwh’s, the unit of measure used on your electric bill.

How much electricity do solar panels produce?

The average amount of electricity produced by solar panels depends on the geographic location they are installed in and the direction and tilt angle they are installed at. Maximum power output over a year will be achieved where solar panels are installed facing south. However, solar panels can face other directions and still be viable. Generally, speaking if production facing south is called 100% then production facing east or west would be 85% of this figure and panels installed facing southwest or southeast would be around 93% of the south facing panels.

More and more owners of residential solar panels are considering installing their solar panels on the more west facing parts of their roof so that they can produce more power in the late afternoon. This is particularly the case in California where time of use electricity billing is used by the investor-owned utilities.

How much do residential solar panels cost?

Residential solar panels cost varies slightly by location and by the size of the system.

The SolarReviews and Solar-Estimate websites both publish residential solar power system cost data on their sites that they collect from users of those sites. They show residential solar panels cost per watt and average residential solar panels cost tables.

Generally speaking solar panel installation cost in America is now generally in the range of $3.00-$3.50 per watt. Given the average size of a residential solar system installed in America in 2018 is around 6.5 kw the total cost of the average solar system in America is currently $21,125 before solar incentives and  $14,787 after the solar tax credit

Are there local utility or state solar incentives in addition to the federal solar tax credit?

Many state based and utility based solar incentives reduce the cost of solar panels in specific areas.

It is often difficult to research solar incentives because there are many incentives that are general in nature and it is hard to tell if they would apply to you installing photovoltaic solar panels for your home.

There is a really good site called which lists all possible incentives for both solar, other renewable energy sources and also energy efficiency programs. Solar-Estimate lists current solar incentives applying to solar panels. Using their solar energy calculator is a quick cheat to finding out what solar incentives you may be eligible for.

How many solar panels do I need?

To answer this question you need to know how much power you are actually using.

In this regard, there is a trade-off between producing an easy estimate of the number of solar panels needed to power your home and producing a more accurate estimate.

An easy estimate can be produced by a solar power calculator just from an average monthly power spend.

However, to get a more accurate estimate of the amount of solar panels you need for your home you need to have more accurate information about your power usage and this requires copies of your power bills.

Often people will use one of the online solar estimators above first to get a ballpark estimate of how many solar panels they need and then if the solar savings stack up they will dig out their power bills and send them to a solar company for proper analysis to come up with an exact solar system size

What is the best option to finance a purchase of solar panels in 2018?

There are many new solar financing options available for allow you to install solar panels on your home without needing to stump up the full cost of the system.

The cheapest solar finance option is usually a solar loan that is secured over your home. This could either be a complete home refinance or a HELOC solar loan which is a line of credit secured over your home. However, typically if you want to use these options you have to sort this out yourself.

The solar companies that will quote to provide the solar system for your home will typically use specialist solar loan providers such as Divdend Solar, Greensky or Mosaic. Here is a list of most of the active solar loan providers to help you find the best solar loan available in your state.