Purchased a home and want to add solar panels? Five considerations to ponder

This week, we have been engaged by three new homeowners to help them evaluate solar. Thereby, we begin with a simple, open-ended question: Why solar, why now? Responses vary, but generally their motive is twofold: Why not, since I just bought my home; and, PG&E’s rates are only going to go up. While we agree with the latter, we believe the former warrants consideration.

Before adding solar to your recently purchased home, here are five considerations:

1. The condition of your roof. Since new homebuyers have recently had their roof inspected, they have an objective evaluation regarding the condition and remaining life of their roof. In simple terms, if your roof has less than 10 years of remaining/warrantied life, you do not want to install solar (on such roof planes); if your roof has 10+ years, you’re in good shape.

2. Historical/future electricity use. Since new homeowners have limited (or zero) electricity use data, we recommend one of four approaches (to forecast future use and accurately size and model their prospective solar system):

• Live in your home for 12 months and, thereby, quantify how much electricity you will use.

• Wait until you have occupied your home for six months -- particularly 1-2 months of summer use, when electricity demand peaks. (Thereby, we can model 12 months of electricity demand based on your use pattern and comparable homes).

• Employ comparable homes’ electricity use (based on their vintage, neighborhood, size, occupancy, etcetera) to model your home’s future electricity use. Fortunately, we have several hundred data sets — electricity use patterns for homes in all neighborhoods in our community — to approximate future use.

• If it’s not too late, request 12 months of PG&E data from the home seller. Oftentimes, this is a futile effort, but it’s worth trying.

3. Home improvements. Stating the obvious: Many new homeowners improve their homes. Adding a pool and/or hot tub will increase your electricity use, as would replacing your furnace with an electric heat pump (an increasingly common practice for Repower homeowners). Conversely, replacing windows, adding insulation, or installing a variable speed pool pump reduces your electricity use. In all cases, we model the impact vis-a-vis solar system sizing.

4. Electric vehicle. If you own — or intend to purchase, in the next 12-24 months — an eV, you’d  want to factor future charging of your car into the sizing of your solar system. We find that eVs travel 4 miles per kWh of electricity. The math is simple: Take the number of miles/year you anticipate driving and multiply it by the percentage of charging you believe will be done at home (versus your workplace, public chargers, etc.). Then, divide the number by 4 to quantify additional electricity use (in kWh). For example, if you intend to drive 10,000 miles per year and charge your car 80% of the time at home (fueling 8,000 miles), you will consume 2,000 kWh of electricity.

5. Your electrical panel. Though adding solar does not increase your electrical demand, we need to ensure your electrical panel has sufficient capacity (or space) to accommodate the solar inverter. Furthermore, we will evaluate non-solar changes to your electrical demand — car charger, spa, swimming pool, heat pump, etcetera — to determine your panel’s amenability. (We perform load calculations and review your future electricity use with the city or county to ensure solar will work.)

 Net-net, going solar is simple, but there are a few nuances worthy of consideration … particularly if you recently purchased a home. Feel free to contact us to learn more and receive a free solar assessment.

Frequently Asked Questions About Solar

[Originally posted February 26, 2015]

How much does a solar system cost?

In the first nine months of 2013, the average per-watt cost of residential solar systems installed in Yolo County was $4.90. Through RepowerYolo’s group purchase program, you will receive the same or higher-quality system at a significant discount, generally 15-25% less than average market prices. For example, a typical home will have a 6 kW (DC) system with a turnkey investment of $24,000 (or less). Your system’s size and cost will depend on your home’s energy use and how much of your PG&E bill you would like to offset.

We are able to offer you a significant discount by aggregating the purchasing power of Yolo County residents and, frankly, by significantly reducing sales and marketing expenses (and the profit we generate).

Are PG&E’s rates going to increase?

Over the past 30 years, PG&E’s electricity rates have increased an average of 5.7%; individual years were highly unpredictable, ranging from -3% to more than 8%. PG&E recently requested, in its California Public Utilities Commission rate case, an increase of $5.33 billion in rates over the next three years. If PG&E’s request is approved, electricity rates will, on average, increase 18.8% in 2014, and 6% per year in 2015 and 2016. To be conservative, our analysis for your solar system assumes only 3% annual PG&E cost increases.

PG&E puts you in a tough position: They operate a regulated monopoly (as the only provider of electricity), and you have no say over rate increases. Your bill simply increases. However, with solar you will benefit from PG&E rate increases. Generating your own power locks in the rate you pay for the next 25 years … as PG&E increases its rates, your savings magnify.

Will solar increase the value of my home?

Yes, if you own (versus lease) your solar system. The National Bureau of Economic Research (NBER) recently released an analysis that found solar panels add between 3 percent and 4 percent to the value of a home. Their conclusion is consistent with a 2013 Lawrence Berkeley National Laboratory study that found solar panels have a “sizeable effect” on home prices.

Can I finance my solar system?

Yes. We work with a number of community banks that provide competitive financing alternatives, and we can help you obtain and assess such options. Furthermore, your home may qualify for financing through Clean Energy Yolo PACE financing program. Clean Energy Yolo funds 100% of the solar system costs, with payments collected through your property taxes over a 20-year period. If you sell your home, the benefit of the solar system (along with the responsibility to make property tax payments) transfers to the new owner.

What rebates and incentives are available?

You will receive a Federal Investment Tax Credit of 30% of your total system cost – in essence, a 30% discount (since it’s a dollar-for-dollar tax credit) incentive to go solar. The Investment Tax Credit is available through the end of 2016 and may be carried back one year or forward for 20 years.

What are the warranties?

The solar panels and power inverter have standard, 10-year warranties. The panels have a 25-year production warranty, guaranteeing power generation.

How long will my solar system last?

Most solar systems outlast their 25-year production warranties; many of the first solar systems installed more than 30 years ago are still going strong. 

Is it difficult to switch to solar power?

No. Repowering your home with solar is simple and hassle free. We will get your solar system up and running as quickly and smoothly as possible so that you can start saving money and using clean energy. You won't experience any changes or disruptions inside your home. 

What determines how well my system generates electricity?

The efficiency of generating electricity is primarily governed by the amount of light (photons) striking your solar panels. Panels facing south and tilted at an angle equal to your latitude yield the best yields. Shade from trees, other obstructions, or even clouds reduce – but do not eliminate – electricity generation. Other factors influencing generation are related to the efficiency of panels, the inverter, and the quality of the installation (wiring, connections, heat-reducing construction). Optimally oriented, high quality, stationary panels and inverters installed with best practices convert 13-18% of sunlight into electricity.

How do I benefit from electricity generated but not used immediately, and do I need batteries?

PG&E’s grid acts as your battery. When you produce more than you use, you generate credits that are applied against what you use. You only pay for the power you use.

What happens when it’s cloudy, raining or at night?

Under PG&E’s Net Energy Metering program, you receive a credit for every kilowatt hour of electricity your solar system generates. You will maintain connection to PG&E’s grid and will thus continue to draw power from PG&E (regardless of whether your solar system is generating electricity).

How long does it take to install my solar system?

From start to finish, the process will take less than one month – our goal is to get your system up and running as quickly as possible. The length of installation depends on the complexity of your roof, the permitting process, and PG&E interconnection.

How am I credited for the electricity my system makes?

PG&E’s net-meter, replacing your current meter, will track the power moving both directions – that is, the electricity produced by the system and sent onto the grid and the power drawn from the grid. Every six months, PG&E will “true-up” your electricity use and solar electricity generation. With solar, there is no disruption to your electrical service. The only change is a reduction in your PG&E bill.

Should I wait for new technology?

No, now is really the best time to invest in a solar system with the combination of proven technology, reduced solar system costs, ever-increasing PG&E rates, and Federal tax incentives. The underling benefit of turning sunlight into electricity will not change for as long as we still use electricity to power our homes.

What about maintenance?

Your solar energy system requires very little maintenance, largely because it has no moving parts. There is no need to wash or dust photovoltaic panels, but it is important to keep them clear of shade and debris to maximize power generation. We suggest you keep an eye on trees that may shade your system and keep them trimmed. Fortunately, the rain serves as a natural cleaning agent, and occasionally you may want to hose down your panels during dry seasons. When you repower your home, you receive one year of free monitoring and maintenance to ensure your solar system is operating at peak efficiency.