Looking for a solar consultant

Good questions Philip.

I ended up designing and purchasing my own system, handling all the permit work and inspections, and having a solar company do the physical installation. Worked great and saved some bucks, but the permit paperwork is not for the faint of heart. My general recommendation is to collect a bunch of quotes using something like energysage.com.

1. How big? (kW) - really depends on your usage (or roof limits). Generally, you want to produce slightly less than you use. Most companies will ask for electric bills to perform this sizing calculation.

2. PowerWall/Battery - can be great for backup, almost impossible to justify otherwise. Generally won't reduce your bill. We have net metering, so the grid is your battery already.

3. Aggregation. Not exactly sure what you're asking, as there are different meanings to aggregation.

4. Solar Water Heating. Almost never a good idea. Very expensive. If you want solar water, it's generally cheaper (initial and running costs) to add more solar power (kW) and buy a heat-pump water heater. Solar Water only makes sense when roof space is highly limited.

5. Suitable for your neighborhood? I don't understand the question. Why would your neighborhood matter?

Best of luck!

We recently went with SunRun through Costco. I got 3 proposals and Sunrun was the best. An advisor will come to your house and teach you everything. They calculate how much energy your system will need to generate based on your utility bills over the last 6-12 months. Other places can create a system for you over the phone based on what you desire battery/no battery etc.

good luck!

Terrific, Philip! Going solar is definitely the way to go, IMHO. I had a grid-tied solar electric system installed on my home about 12 years ago, and added it to it with the addition of a plug-in electric vehicle 9 years ago. The industry is constantly evolving, particularly as local jurisdictions and utility providers adjust and shift priorities. When my system was originally installed, I was not allowed to install a system that provided more than 80% of my anticipated use. Now, PG&E will pay me for extra power generation.

I am a (retired) architect, so I knew a reasonable amount going into my projects. That said, I would not recommend hiring a consultant. Do your research to find qualified installers that serve your area - ask your neighbors, friends, colleagues, ask at the local building department which installers pull a lot of permits and they may share with you their opinion of which are professional and easy to work with. Read what you can from reliable sources on the internet. Then, choose three installers from which to solicit proposals. Go to them with a written outline of your project goals and let them know you are soliciting three proposals. They will send someone out to meet with you, see your property and take various measurements. They will provide you with a design and cost proposal. Evaluate the three - pretty much guaranteed they will be quite different.  Ask clarifying questions and get an additional proposal if you think you need it. Make your decision and enjoy watching your electric meter run backward!

Good luck with your project!

A consultant is likely way overkill for a residential system. I recommend getting quotes from a handful of installers (maybe 5) and then comparing them. Just ignore the sales pitch and tell them you’re paying cash. You will find that most installers size the systems similarly in terms of kw because they’re using the same formulas so you’ll have an apples to apples comparison. There’s basically no maintenance and little quality difference, so those are not really issues. 

If you’re looking to make the best financial choice, battery systems aren’t financially viable yet. You can do it, but you’ll never break even on the system. If it’s not about money, they’re worth considering for backups for short power outages for critical items in the house. To setup an “off grid” capable battery system for all power takes a lot of space and money and is really unlikely to make sense for most people.

As a general rule, doing solar electric with a high efficiency electric hot water heater is less complicated than solar hot water. I’ve struggled to find good plumbers for solar hot water and the ones who can do it correctly are not cheap. Those systems require an expansion tank, tempering valves (the water often gets too hot) and back up water heating  for cloudy days. To me, it’s not worth the extra headache and space and money they require particularly given that you still need a “regular” water heater as backup anyway. They are neat though. And once they’re common enough that any old plumber is confident setting them up, I’ll consider making the switch.

You've received a lot of good information, but some may NOT be relevant or correct for your situation--depends on where you live, size of your system, what rate schedules are open to you.

Specifically, if you live in East Bay Clean Energy territory (Community Choice energy in many East Bay cities) and your system produces more energy than you use over a year, EBCE gives you retail rate for the excess  https://ebce.org/net-energy-metering-with-ebce/  unlike PG&E which gives you wholesale rate--approx 3-4 cents per kwh.  And since you say you may want to add electric appliances, maybe an electric vehicle, "oversizing" your system can make sense.

I agree with those who suggest you get multiple quotes.  If you are willing and able to look hard at the details, ask lots of questions, and push to talk to a knowledgable company representative, then I don't think you need a consultant...