A new limited time PG&E energy efficiency rebate where you can receive up to $3,500 in rebates from PG&E’s Energy Upgrade California pilot program. Limited to first 500 homes. San Francisco, Berkeley, San Mateo County, and other parts of the SF Bay Area and Northern California are in the PG&E service territory.  SMUD of Sacramento has its own similar program.

Qualification:

• You must own a single-family home or duplex and be a PG&E customer.
• You must be current on property taxes and liens.
• The amount of the rebate you get is based on energy modeling software that shows how much energy your home will save after an energy upgrade remodel.
• A home energy audit which includes energy modeling must be completed by a certified energy auditor.
• The rebate amount is based on how much less energy your home will use after the energy upgrades. A minimum 20% energy reduction receives $2,000 in rebates. Each additional 5% reduction beyond that earns another $375, up to $3,500.  (see chart below)

California Building Performance Contractors Association is certifying contractors working within the EUC PG&E Home Performance programs.

Contact your local Home Energy Audit firm today.

• Hire a home performance firm to perform an energy audit of your home.
• Work with your specialist to choose and implement cost-effective improvements to achieve your desired energy use reduction.

Be sure to take advantage of the Federal Tax Credit too!

Solar Power for less.

Sungevity has a $0 down Solar Panel Promotion for those in California who sign up for a solar lease through.

Solar Day is Saturday June 19, 2010, a Nationwide day to learn about Solar Energy.  A day of recognition for solar energy, energy independence and protection of the planet. Check your local area for events, solar home tours, etc.  San Francisco has a Green Energy Fair on Saturday, June 26, 2010.

Be sure to read our article:  Are solar Panels for me?

The Earth receives more energy from the Sun in one hour than the whole World uses in a whole year.  Time to tap into that. Solar power is used to power everything from calculators to Coast Guard buoys to highway signs to the International Space Station.

You have read Are Solar Panels for me? and Solar Panel Installation – Planning and are ready for more details. Photovoltaic Solar panels were invented at Bell Labs in 1953. They have evolved over the years and several different types of solar panels exist, and choosing between then is confusing.  No one vendor will have access to all products, so you will have to do some shopping around to find the best solar panels.

Monocrystalline or Polycrystalline Panels

These solar panels are made either from single crystal cells or stringing ribbon of multiple crystals. They are the classic version of solar panels and are rated for good efficiency, around 12-13% power conversion, and a Long lifespan, possibly 30 years+?  Sunpower has a model with a very high 19.3% efficiency.  Monocrystalline panels are less efficient in hotter climates and work best in unobstructed sun. A panel’s power will drop by 50% if a even one cell on the panel is half shaded. Temperatures typically above 75 degrees F cause most solar panel power generation to decrease. Solar panel suppliers include: Sharp, Hitachi, Mitsubishi, Kyocera, Schott, SolarWorld, SunTech, Sunpower, bp solar.

Thin Film Panels

Less efficient than the Crystal Panels, but they much thinner and easier to make.  Less efficient than monocrystalline, at 10-12% efficiency. They work better when you have slight shading and are not affected by hot weather as much as monocrystalline. Major Drawback of performance degradation over time.  Possible lifespans of 10 years. Suppliers include: Nanosolar, Unisolar

Hybrid Panels

Hybrids of single crystalline silicon surrounded by ultra-thin amorphous silicon layers.  Produces 10% or more electricity  (kWh) than conventional crystalline silicon solar panels at the same temperature. Good efficiency levels of 16%. Hybrid Solar Panel Suppliers include: Sanyo

Solar Panel Power Ratings

Solar Panels are rated by Maximum power generated or Pmax that they produce in Watts when exposed to full sun.  The rating may be calculated at STC - Standard Test Conditions at the factory or PTC – Practical Test Conditions which are more real world.  PTC numbers are almost always lower than STC numbers. Most spec sheets will also show how much power they make with varying current and voltage. To calculate total system power, you need to compare Apples to Apples.  Power output of solar panels decrease with time. Many panels are rated for 80% output for 25 years, 90% output for 10 years.

Also look for the negative tolerance rating of solar panels. This number reduces the PTC rating, so a high PTC rating with a high negative tolerance is not good.  A 200 watt PTC panel with 10% negative tolerance could produce only 180 watts.

Look for the installer to quote a minimum warranted power rating for solar panels.

Total Solar System Power in CEC AC Watts output = Number of Panels X PTC Power rating of each Solar Panel X Inverter efficiency.

3456 watt CEC AC Rating = 3.4 kw = 12 panels X 300 Watt PTC Rating x 96% Inverter efficiency

This is a real world power output ratings of a solar electric array.

Solar Panel Inverters

Inverters convert DC power from the solar panel to AC power you can use.  Look for brand name inverters from Sunny Boy.  Target inverters with 95% or higher efficiency and 10 year warranty.  Options include web interface to get statistics, SD Card for holding data, or even WiFi access.

Solar Panel Warranty

Look for a solar panel that has a long warranty. The longer the warranty, the more reliable the vendor feels the solar panel is. 20 or 25 years is not uncommon. Life expectancies of up to 40 years are now being seen. Watch out for dealers that promise warranties that may outlive their firms.

Solar Panel Rebates

Most rebates have lists of qualified solar panels.  This can help narrow down what you can buy. California has a list.

The solar panel that is right for you, depends on your budget, location, and power needs.  Some installations may need different types of panels for different locations, especially for areas of no shade and partial shading. Consult a local expert to find what is right for you.

Beware of the latest technology, you do not want to pay thousands of dollars and be a beta tester.

You have read Are Solar Panels for me? and decided that Solar Panels are in your future. Planning a new solar installation requires lots of analysis and planning.  You need to size your solar system, select solar equipment, select a payment option, and find a qualified local solar installer.

Sizing a Solar Electric System

Power Usage – Grab the power bills for the last year. How much power do you use in a given year?  What rate plan are you on and what is it? Do you want to zero out your bill (most environmentally friendly) or just reduce your bill (financial benefit) by moving to lower price classes? It may be more cost effective to fall into lower price tiers. In the San Francisco Bay Area most PG&E customers have tiered energy pricing (E1 Residential Pricing plan) that starts at 12 cents, but jumps to 14, 29 cents, 40 cents and 40 cents as you use more power. The solar installer you select must be able to help you here.

It pays to reduce your electricity consumption by conservation and efficiency BEFORE you size a system.  Read our tips on saving electricity.  Each $1 spent on efficiency saves almost $3 in solar costs. Consider a home energy audit.

Sizing your system – Examine your roof size, power bill, solar panel efficiency, and see how large a system you can actually install.  You may be limited by space on your roof. The very nice California Clean Power Estimator takes your power usage information, physical location information, incentive information to give you savings estimates based on solar panel size.  Other states may have similar tools.

San Francisco has a nice solar map. It shows various solar system installations and how much solar power and money savings you can expect from your location.

Select Solar Equipment

Solar Panels – Picking the right solar panels is determined by how shaded your location is, your budget, and your efficiency needs. Be sure to compare panels using AC watt ratings.

Power Inverters – These units convert DC power to AC power. Each unit can only handle so many solar panels. Newer models have better efficiency at converting power. How many inverters do you need? Where will they be positioned?  Do you leave room for future solar panel additions? Some communities require them to be in the shade and away from fire hazards.

Paying for Solar Panels

Many people do not have $30k sitting around. Do you want to buy or lease solar panels? Both have advantages and disadvantages.

Optimal Installation Date

The optimal time to get your solar panel installed is in early spring/late winter, avoid installations in fall if possible.  Very little power is produced when the days are short or when the sun does not shine.  The biggest factor affecting an  installation date is usually when tax rebates ends or when they ratchet lower.  Try balancing the two factors to optimize your solar electric system install.

Utility Company Interaction

Most utilities offer credit for excess solar electricity provided to the utility but not used by the home. When you have your solar panels installed, you should be able to select “time of use” billing where during peak times (Weekdays 1-7pm) in the summer, you generate more power than you need and collect energy credit for the lean winter months. The rates are 2.5x higher in summer, so you can earn a lot of winter offsets. They will also have an interconnection agreement for you to sign.

PG&E has a section on their Solar Energy section on their website. Netmetering changes your power bill to an annual cycle. Our power bill is still charged a minimum $5 a month. At the end of the year, we pay them how much PG&E power we actually had to use.

Finding a Qualified Solar Installer

After reviewing the above criteria, the next step is to contact a local Solar Panel installer.  They will first look at your property via online tools to see how your roof looks, examine your power bills, evaluate your goals, and see how your property is oriented.

Solar Electric installers should then visit your location to inspect it. Expect a customized solar system design, financial analysis, and options for financing.

A solar electric quote is a detailed quote a system tailored to your budget and home.

As with any vendor, look for one with a solid track record, solid references, and competitive pricing.

Questions to ask a solar electric system installer:

1. How long have you been in business, how many installations?
2. What is the minimum warranted power rating of the solar panels?
3. What is the PTC per watt rating of the solar panels?
4. Who makes the solar panels, how long have they been shipping these, factory warranty?
5. How efficient are the solar panels and power inverter?
6. Who makes the solar panels and power inverter?
7. Who makes the solar panel mounting racks? Are they commercial grade?
8. Get a quote for a solar electric system that will zero out your electric bill and a quote for a smaller system that will kick you into the lowest electricity tier.

California has a database of Solar installers, contractors, and solar panel dealers. California Solar Energy Industries Association

Be sure to read our solar panel deals page for the latest updates in special promotions.

Once your Solar electric system is installed, you will need to maintain them as  Solar Panels will need occasional solar panel cleaning.