Solar Electric Systems
Photovoltaic (PV) systems provide several benefits conventional grid-powered electricity does not.
- Free fuel (photons from the sun)
- Stable energy costs for decades to come
- 98% reduction in greenhouse emissions
- Locally produced fuel for electric vehicles
- Solar panels leave no waste
- Energy indepedence!
What are PV systems and how do they work?
A solar electric or photovoltaic (PV) system generates DC electricity from photovoltaic modules, sends it to an inverter that converts it to AC, and into your house electric panel. Your electric meter spins backward when your home isn't using the energy generated, giving you retail credit for power produced. Through net-metering the utility company measures the remainder of energy that you consume minus the amount that your PV modules produce. You are charged only for this amount on your electricity bill. If your system produces more electricity than you use you will receive credit that can be carried over month-to-month (but not year-to-year, with April 30th the cutoff date).
In Washington State a separate production meter is also installed that measures the total amount of electricity produced by the PV system. Each year you will be paid a reward for all the solar energy that you have produced, with the amount based on the type of system installed. These generous production incentives, established in part by the lobbying efforts of Puget Sound Solar, have made solar PV systems more cost effective by reducing the payback period.
How much can PV produce?
For each 1000 watts, or kilowatt, of PV you can get up to 1,200 kilowatt-hours (kWh) of electricity produced per year in Seattle. To see what this means, check your electric bill to see how many kWh of electricity you use. The average home in Seattle uses 8,600 kWh per year.
What is the installed cost of PV systems?
We offer different ‘flavors’ of PV systems based on the products used: The lowest initial cost, the highest production per square foot, and the fastest return of investment. The cost can vary depending on your goals, and the difficulty of installation. Expect costs to range as follows:
- 8.5 kW $22,000 - $36,000
- 5.5 kW $17,000 - $25,000
- 3.5 kW $11,000 - $17,000
For locations that experience power outages, there are solar electric systems that also provide back-up power, instantly and silently. These use dual-purpose inverters and batteries will produce electricity for as long a period as the battery capacity and solar input will support. These systems are programmable, so that they can also be used for daily 'self-consumption' of power to reduce demand dependence on the grid. Plan on spending about $10,000 - $30,000 for the additional design, equipment, and installation labor. Off-grid locations use battery-supported PV systems that also integrate a generator for dark winter months or perhaps a wind generator as well. Tesla's Powerwall combines battery, inverter, charger, and controller in one package. If you already have a generator, your battery system will be installed 'upstream' from the generator, making the battery the 'first responder' in the event of an outage. If the battery becomes depleted, the generator will then take over.