Thinking about installing a solar energy system? It’s a great choice to take advantage of the abundance of sun we get in Marin and to increase the eco-friendliness of your home or business while potentially lowering your energy costs.
So where do you start?
These questions can help you decide if solar is right for you.
What Do I Want My Solar Energy System to Do?
Different types of systems do different things. Do you want to power your lights and appliances? Provide hot water for you your family? Heat your pool?
For homes and businesses, you can generally choose between two types of solar energy systems:
Photovoltaic Systems use panels (usually placed on the rooftop) lined with cells that absorb sunlight and covert it to electricity. An inverter changes the alternating current (AC) to direct current (DC) so it can be used by the electrical grid. This kind of system can provide electricity to power your lights and appliances, and your electrical heating/cooling systems.
Solar Thermal Systems use the sun’s energy to heat water, either for household use or for pool heating (or both). In a climate like the Bay Area’s, with little risk of freezing, a common type of system uses panels lined with thin tubes that absorb sunlight to heat water, which is then pumped into a storage tank for use. Like photovoltaic panels, thermal panels are usually mounted on the roof.
To heat a pool, the system generally uses a pump to send water to a solar collector for heating. The heated water is filtered before being pumped back into the pool.
How Well Will a Solar Energy System Work in My Location?
Most systems rely on sunlight collected from roof-mounted panels. To maximize the efficiency of a solar energy system, your roof should:
- Receive direct sunlight during most of the day
- Face south (best), or southeast or southwest
- Have a moderate slope
- Have a large surface area not broken by many skylights or other interruptions
- Be in good condition
Even if your roof doesn’t meet all of those criteria, you may still be able to use solar energy, but the efficiency (and cost savings) of your system will be reduced.
How Much Will It Cost to Install a Solar Energy System?
The cost of installing a solar energy system will depend on a number of things, including the type and size of system, whether you decide to lease or buy equipment, and other factors.
Let’s start with the basics of leasing vs. buying:
Leasing
When you lease your solar system equipment, you generally pay nothing for installation. You will pay a monthly fee that may increase over the period of the lease (typically 20 to 25 years). The company that owns the system will install it and take care of maintenance.
Your up-front costs will be considerably lower than if you buy, but you will not get the benefit of any rebates, tax credits or other incentives.
Depending on the terms of your agreement and your typical energy use, you may realize lower savings from reduced energy bills than if you owned your system.
Be aware: if you plan to sell your home prior to the expiration of your lease term, the buyer may be required to take over your lease or buy it out.
Buying
The up-front cost of installing a solar system varies, but is generally between $10,000 and $30,000. You may be able to get a loan, either from a solar company or a third-party institution, to finance some or all of the purchase.
The cost of installing a solar energy system can be offset by federal and local rebates, tax credits and incentives; how much will depend on what’s available in your local area and whether your system qualifies. In 2022, Congress extended the federal tax credit for residential solar; the current federal tax credit is 30% of the cost of an (approved) system instlled between 2022 and 2032. The federal credit will drop to 26% in 2033 and 22% in 2034, expiring in 2035, unless the program is renewed. (Federal credits work differently for commercial properties.)
North Carolina State University runs a website, DSIRE, that includes a database of clean energy policies and incentives by state.
How Much Will I Save on My Energy Bill?
Again, your savings will depend on numerous factors, including the size, type, and efficiency of your system, whether you lease or buy your equipment, and your current energy costs.
Here in Marin, both PG & E and Marin Clean Energy have tiered rates that depend on your energy usage: the highest energy users pay the highest rates, so they are likely to reap the most long-term savings from a solar energy system.
Google’s Project Sunroof has an easy-to-use online calculator that will estimate the usable sunlight for your roof, the size of the system you need, and give you a rough estimate of potential cost-savings on a purchase or 20-year lease of photovoltaic panels.
More Solar Resources
GoSolarCalifornia.org has information about the California Solar Initiative, and how to earn incentives for going solar.
CleanEnergyAuthority.com has lots of resources, including information on rebates and incentives by state, county and city.
The County of Marin website has information on the Marin Solar Program, and resources to help you evaluate the benefits of installing a solar energy system for your Marin home or business.
A version of this post first ran in 2016. It has been updated to reflect changes in solar energy subsidies.