There are many variables that go into the cost of a solar PV system. Like all major purchases, there are many decisions to make. How big of a system do you want? How efficient of a system are you looking for? What is the quality of equipment you’re purchasing and where was it made? Are there special installation considerations?

PUD 3 is finding that you can expect to spend between $3,000 - $8,000 per installed kilowatt (KW) of designed capacity. PUD 3 recommends getting at least three bids and selecting the contractor you feel the most comfortable with that offers the best product available within your price range. Please see the section of the guide linked above entitled "Working with a Solar Contractor". 

There are two wind generators connected to PUD 3’s grid, and they are about 3 KW in design capacity.

Home Power is an excellent magazine/website for people interested in generating electricity at their home. They published a great article in May/June 2015, Issue #167, called "Wind Turbine Buyers Guide 2015" that would be a great resource. 

That depends on your roof and home. Your solar contractor will be able to make that recommendation. Be sure to ask your solar contractor about how your new solar PV system will affect your roof warranty, as well as any leaks or damages that occur as a result of the solar PV system.

If your roof is older and in need of being replaced in the near future, you may want to defer installation of your solar PV system until that is completed.

Check your local city or county building department for applicable permit information.

The short answer is NO. PUD 3’s linemen must have access to an AC disconnect switch to disconnect your solar PV system during an outage. This prevents the system from back-feeding, or sending energy onto the grid, which would endanger the PUD 3 crews working to restore power. Additionally, PUD 3 requires inverters to have an automatic voltage-sensing disconnect switch built into them to prevent backfeeding. This redundancy is for the safety of PUD 3’s linemen and other personnel. 

Adding a battery backup/storage option to your solar PV system will greatly increase the cost and return on investment. You’ll need to consider the initial cost of the batteries and the maximum projected life (measured in "cycles" – charge and discharge). The high cost and short life of the batteries, when compared to your solar PV system may affect your decision.

If you’d like a backup power source during outages, an efficient generator will likely serve you better than a battery bank. Most of our power outages occur during winter storms when days are short and solar PV systems are producing little power to recharge a battery bank. Battery power is short lived and extremely limited. Please see PUD 3’s web page on Generator Safety for more information.

Since a solar PV system is made up of panels that have a sturdy tempered glass surface (naturally sheds water and dust) mounted 4" – 8" above the roof to prevent debris from building up underneath, they’re generally maintenance free. However, for maximum efficiency, it is recommended to wash the face of the PV panels at least once a year.

A solar PV system that tilts the panels to track the sun in order to optimize energy production has motors that will require regular maintenance.

Let’s just say, the more sun you put in, the more electricity you’ll get out! To learn more about factors that both enhance and limit production of a solar PV system, take a look at the section in our guide linked above that covers other things to consider when evaluating is solar PV is right for you. 

This comes down to the efficiency of the solar cell, which "collects" the light energy, and it’s a simple exercise in scale. If you have a collector that is 20% efficient, which is on the high side for solar cells available on today’s market, it will absorb about 20% of the light that hits it. If you shine a lot of light on it (direct sunlight), the total amount of useful light for the production of energy will be much higher than if you shine a very little bit of light on it (ambient light). So, while "ambient light" may be able to generate a small amount of electricity from a solar PV system, it will greatly reduce the actual capacity factor of that system.

Passive solar is a building design principle or strategy that uses the design and placement of windows, walls, and floors to collect, store, and distribute solar energy in the form of heat in the winter, while rejecting solar heat in the summer. Unlike a solar PV system, passive solar doesn’t use mechanical or electrical devices (e.g. solar PV panels). 

Solar water heating is more often found in hot, sunny climates such as Arizona or Hawaii than Western Washington, where we have a shorter solar season. A solar water heater is mounted to a home’s roof to take advantage of the sun’s radiation to heat or preheat water before use in the home. A closed loop system of heat transfer liquid is mounted in a collector panel below the tank and is heated by the sun.

The hotter liquid rises in the system, which comes into contact with the domestic water. The heat energy is then transferred to the water in the tank. Once the heat energy is released into the tank, the liquid continues flowing back along the loop, into the collectors, and the cycle continues. If there is inadequate solar heat gain and the water doesn’t reach the desired temperature, a standard electric or gas water heater is used to add heat until the water reaches the desired temperature. Many systems are passive, closed loop systems, but some require a small circulating pump. There are many various technologies used in solar water heating worldwide. 

Comparing solar generation with anywhere except Mason County is a frustrating task. There are so many variables that go into the production (see: Capacity Factor) and financial benefit of a solar PV system. A comparable position on the globe certainly isn’t helpful because local climate isn’t a latitude/longitude based system! You also should consider the political climate, which varies greatly from state-to-state, as well as between different countries.

Germany has been a global leader in installed solar capacity and is often put forth as an example of why solar PV is a great idea for Western Washington, because we’re at approximately the same latitude, with a similar solar radiation score. It’s important to also consider the political climate for solar PV systems in Germany. The German government has heavily subsidized the installation of renewable energy through many measures over the years. There are also lucrative "feed in tariffs" allowing owners of distributed generation systems to sell power back to the grid at very favorable rates. Permitting for solar PV systems, and the systems themselves are also cheaper in Germany.

It should also be mentioned that there is a price to pay for these "favorable" conditions: the average cost of electricity in Germany is $0.35/kWh, which is among the highest in the world. To compare, USA is about $0.12/kWh and PUD 3 is a little more than $0.07/kWh. Unfortunately, these incentive and pricing structures can mask true evaluation on whether solar PV is a good fit for a "comparable climate" such as Germany.

Check out Let's Go Solar. Their page on solar power in Washington state is interesting as well.