Thursday, March 14, 2019

How to go solar (+ Day #4 off-grid)

From time-to-time I get cold-called by a stranger who wants to sell me a solar system.  I wouldn't buy anything from a cold-call, much less something with the price and complexity of roof-top solar.  

The good installers stay in business under the same name, and stand behind their work.  They guarantee the roof against leaks caused by their installation, which they can well afford do because a careful, professional solar installation does not create roof leaks.  They do not call random strangers on the phone.

Rooftop solar now costs less than $3/watt installed.  We've seen prices on large installations at less than $2/watt.  The price will vary with the hardware installed, the type of roof, and the size of the system.  Batteries are extra - a lot extra.  Installers also give discounts for group purchases.

The solar co-op makes group purchasing easy

A couple of years ago, local solar aficionados were celebrating the great and glorious defeat of the deceptive solar amendment pushed by FPL and Florida's other investor-owned utilities.  The utilities's sneaky amendment was designed to thwart residential solar, and it went down in flames once the voters learned of the ruse.  The League of Women Voters (LWV) called a meeting to promote the idea of creating a solar purchasing co-op program in Miami-Dade County through a national non-profit called Solar United Neighbors, The LWV asked for volunteers to make it happen.  

Coconut Grove resident Jody Finver stuck up her hand because she wanted to devote her every waking hour to promoting solar in Miami-Dade County.  

I stuck up my hand because I knew where to get the money to hire someone like Jody.  I sit on the board of the Green Corridor, an interlocal group that includes Cutler Bay, Palmetto Bay, Pinecrest, South Miami, Coral Gables, Miami, and Miami Shores.  We run a financing program for energy efficient home or business improvements, and we had a little money in our do-something-good account.  We agreed to fund the solar co-op program.

After interviewing applicants, Solar United Neighbors hired Jody as the first ever coordinator for the Miami-Dade Solar Co-op.  They had to - she's amazing.  Her taller half, Simon Rose, is pretty wonderful too (photo credit Chevrolet).  That's their house.

Jody sets up solar purchasing co-ops in Miami-Dade County several times a year.  Look for these at  Dozens of local organizations have officially endorsed our solar co-op program, including local governments and local environmental organizations.  [If you live outside greater Miami, look at Solar United Neighbors main website for co-ops elsewhere].

The solar co-op costs nothing to join and there's no obligation to purchase.  What you get is the experience and hard work of Jody and the organization.  They put out RFPs (requests for proposals) to regional solar installers.  They know how to write the bid specifications so you don't have to.  The bids might include various options such as high-efficiency panels or batteries.  At some point the co-op closes to new members and the process continues forward.  The entire co-op membership decides democratically what criteria are most important (e.g., duration of roof-warranty, price, experience, etc.).  A group of members volunteers to be on the selection committee that reviews the bids.  The committee evaluates the bids based on those criteria and selects ONE installer.  At that point, any co-op member has the option of signing a contract with the chosen installer.  

If you already own a house and you want to add solar or solar+batteries, I always recommend to GO WITH THE CO-OP.  That gets you a good price and a professional consumer advocate (e.g., Jody or local equiv.)  to assist you with the process.  If you are building a house, and can't work around the schedule of the co-op, I can recommend some reputable installers for you to interview yourself, some of which offer "South Miami pricing".

Jody says to tell you...  
"Last information session for the current Miami co-op is March 19th - sign up online.  The current co-op is open to new participants through April 19th.  Also, 2019 is the last year for the 30% Federal Tax Credit.  In 2020, the Tax Credit steps down to 26%. In 2021, it steps down to 22%, and in 2022, it’s gone."  [...unless we can convince the Congress to extend it]. Any tax credit obtained but unused can roll forward to the succeeding tax year.

What about the fabled Tesla solar roof tiles?  As of today, Tesla's solar tiles still have not been certified for the Florida market, which requires a crazy-high wind-rating.  The tiles super-strong, but certification has not happened yet and production is still scaling up.  Tesla recommends people in Florida get conventional solar panels.  I don' t expect that the serial connection of solar roof tiles can finesse the problem of partial shading, whereas several solar inverter systems for conventional panels can accommodate partial shade without compromising productivity of the whole array.  If you have trees nearby, partial shading is an issue to consider.

Batteries are not needed unless you want to use solar power in lieu of a whole house generator.  
In the power outage that followed Hurricane Irma, approximately half of the whole house generators in South Miami failed. Some were repaired fairly quickly, but others needed back-ordered parts.  One family would up in the hospital with carbon-monoxide poisoning because they'd installed their generator too close to the house, without pulling a permit.  The one in this photo stayed functional because the owner had a good service contract that tested it every month.  A neighbor's generator developed bad bearings that squealed terribly.  For two nights we prayed that it would fail, and on the third night our prayers were answered and we were able to sleep with the windows open.

For these reasons, many people would prefer solar+batteries.  

Solar systems have come a long way since Jimmy Carter put them on the Whitehouse lawn. Prices fell exponentially, but now have leveled off.  By contrast, home and car batteries are at the beginning of a revolution.  Expect big improvements in the technology and falling prices for the next 40 years.  Still, who can wait 40 years?  Let's get on with it!  Several home battery systems are available at this time, and more are coming along.

The solar double-whammy: clouds on laundry day

If it's sunny on laundry day, I can break even with solar, but not if it's cloudy.  No big deal if we're on grid, we just borrow a little power from the surplus credit we get from net-metering. But if we're off-grid and run out of power, I can't run next door and ask the neighbors for a cup of electrons.  Well I could, I suppose, but they'd just say "Maybe you should just turn the power back on."  My neighbors are sensible like that.

I started the day with a 56% battery charge.  Five loads of laundry ran through the clothes washer and dryer while I was in meetings.  How did we manage to generate five loads of laundry?  We've had five people in the house this week, and some of them have spent their days at the beach (extra towels). We could line dry everything if we circled the yard twice round with clothes line.  Then it would rain for sure. 

From time to time, I peeked nervously at the energy flow.  At 11 am, the battery was down to 36%, even as the sun rose higher in the sky.

Then at 12:20 pm it happened - clouds rolled in
I'd feared this.

Could the house make it through a cloudy day running the freakin' clothes dryer non-stop?  If we had not fully charged the car the day before, at least we could have started the day with nearly full battery.  Remember that for next time, but too late now.

The sun played peek-a-boo until sunset when it left us for California.  Clouds also shade the rest of the house, so at least the A/C takes a bit of a rest on a cloudy day.  If I were a nail-biter, I would have bitten my nails.  I was steeling myself for the ridicule I'd get if the power ran out because I'd been too ambitious.  I'd tell them "Hey, that's what experiments are for, right?  We could use this evening to express our solidarity with the folks in Venezuela."  (Sure, Dad.  How about you turn the power back on so we can use the internet this evening to read what's happening in Venezuela and you can resume your experiment tomorrow?).

The next morning I woke up (on fresh sheets), groped in the dark for my phone, and saw the battery reserve was down to 13%.

I briefly operated the toaster and the microwave in the course of making breakfast.  Nobody else was ratting around the house using a hair-dryer or an arc-welder.  The three college kids here for spring break prefer not to rise with the neighbors' chickens (surprise).

At 8 am, dawn's rosy fingers tickled the solar panels and the batteries began to recharge.

It was a squeaker, but the solar house had made it through the biggest challenge of the week.  We should have easy coasting from here, even with some clouds.

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