How PG&E’s “EV” rate schedule benefits solar homeowners

We have had the fortune of helping more than 50 electric vehicle owners go solar. As shared in prior posts, fueling your car with solar electricity is the least expensive form of (automotive) transport: Your amortized cost to generate solar electricity is ~8 cents per kWh, and you yield about four miles per kWh of electricity. Trite but true: Driving on sunshine makes sense.

Better yet, when you enjoy an electric vehicle you can employ PG&E’s “EV” rate schedule. This time-of-use rate program incents EV drivers to charge their car (and shift other electricity demand) to “off-peak” hours, namely 11 pm to 7 am, Monday through Friday, and all weekend/holiday hours, sans 3-7 pm.

Here are PG&E’s “EV” rates per kWh:

• Peak (2-9 pm, M-F): $0.33 (winter); $0.48 (summer)

• Part Peak (7am-2pm; 9-11pm M-F): $0.20 (winter); $0.26 (summer)

• Off Peak (11pm-7am M-F; weekends/holidays all hours except 3-7pm): $0.13

When your solar panels make more energy than your home uses, you are credited by PG&E via their net-metering program. Hence, the greater the delta (solar generation less household consumption) during “peak” periods, your monetary credits are amplified.

Generally, Repower homeowners who enroll in PG&E’s EV rate schedule only generate ~80% of the electricity they use to cover 100% of their electricity costs. This is simply due to the time-of-use rate schedule and the advantage of buying electricity at a low rate and getting credited at nearly 4x. Very cool.

With apologies for the bevy of metrics, let’s review an example. Below is the electricity use for a fairly standard Davis homeowner who charges their electric vehicle 12,000 miles per year at home.

Pre-solar electricity use and costs (on PG&E’s “E-1” program):

We then sized and modeled a solar system to eliminate the homeowner’s electricity bill: A 4.8 kW, 15-panel system installed at 270-degree azimuth (due west), no shading. The solar panels are projected to generate 6,493 kWh in year one, thus covering 70% of the homeowner’s electricity use.

If the homeowner did not own an electric vehicle, they would (upon going solar) enroll in PG&E’s “TOU-A” rate schedule. Like the EV rate, TOU-A values electricity based on demand (“peak” period is 3-8 pm), but there’s little difference between peak and off-peak periods.

Solar economics under the default E-TOU (A) rate schedule:

The homeowner’s year-end, true-up cost would be $645 — the solar system is too small. This is not bad, but …

… under the EV rate schedule, the homeowner generates significant time-of-generation credits/leverage. Their year-end bill would be $108.

Simple but lucrative: The homeowner will save an additional $500 per year through the EV rate schedule. Contact us today with questions and/or if you’d like a free solar assessment.

Understanding your PG&E-Valley Clean Energy Bill

Valley Clean Energy (VCE) commenced service as an alternative electricity provider June 1. As discussed here, this is great news … your electricity costs will be reduced by ~2-3% and you will enjoy (though you can’t see/taste/touch the electrons!) cleaner electricity. (If you’re among the 7,000 property owners in Davis, Woodland and unincorporated Yolo County who have already gone solar, this article has no utility for you; here’s a recent article about Valley Clean Energy’s Net Energy Metering program.)

Now that we’re a few months into VCE’s service, many homeowners are trying to interpret their new (PG&E + VCE) electricity bill. Here’s a quick tutorial:

• Page three of your PG&E statement quantifies your electricity use and charges. (Yes, July was a brutally warm month; electricity use/costs are quite high for most everyone.) Therein, you will see two additions:

1. A Generation Credit representing your Valley Clean Energy credit for the electricity generation component of your use.
2. A Power Charge Indifference Adjustment, essentially the fee PG&E charges to participated in VCE.

Next, turn to page four to review “Details of VALLEY CLEAN ENERGY ALLIANCE Electric Generation Charges”. Per the below, there is a net charge of $93.28.

Finally, simple math to determine how much you will pay relative to PG&E:

- VCE Electricity Generation Charge: $93.28

- Power Charge Indifference Adjustment: $43.90

- Less, PG&E Generation Credit: -$141.43

Hence, under the above scenario the homeowner saved $4.25 this month through VCE.

Annualized, this homeowner will save ~$40 for participating in VCE. It’s not enough to buy a bottle of Jordan cab, but perhaps you can enjoy a tasty meal at Mikuni’s.

Valley Clean Energy works.

Lions and tigers and ash on my solar panels, oh my!

What a brutal few weeks it has been. Our climate is speaking to us: We can see, taste and smell it. And, our solar panels are not happy either. Analogous to what you see on your windshield, solar panels are clouded with ash from the Mendo Complex and Carr fires (of late) and others. Yuck … makes me want to hop on a tree stump and paraphrase Dr. Seuss: I AM THE LORAX AND I SPEAK FOR THE SOLAR PANELS, FOR THE PANELS HAVE NO TONGUES, NOW LISTEN TO ME!

We monitor 200+ Repower homeowners’ solar systems 2-3 times each week, evaluating their solar generation vis-a-vis National Renewable Energy Lab projections. Though it’s at the bottom of residual impacts of the fires — we’re simply talking about electricity generation! — our solar systems are generating 10-20% less electricity over the past 10 days. Some days are worse than others … Monday (August 6) was horribly suffocating for solar panels.

What to do? Here’s an excerpt from an article we composed last summer about keeping your solar panels clean:

As solar panels have no moving parts, the main area of maintenance is to keep them clean. We recommend to check the panels periodically especially during dry periods when precipitating dust occurs with the morning dew. Dirty panels can reduce electricity production as much as 8-12% (results from Department of Energy studies vary). Most dirt can be easily removed with water sprayed from a hose or from rainfall. (Do NOT use high-pressure sprayers as it can damage the seals around the frame.) Important: Wash/spray the panels in the morning to reduce drastic temperature changes. If you cannot ascend your roof, simply spray from the ground and let gravity do the trick … a small wave of water will cleanse most dust. Do not scrub the panels with any harsh materials. If a brush is needed, make sure it has soft bristles, or opt for a common window squeegee. If you notice rapid dirt build up—or bird droppings—then more frequent cleanings are warranted.

Feel free to contact us if you have questions about how and when to clean your solar panels. And, most important, let’s hope the fires cease and our air quality improves.