My spouse and I are very early adopters among those solar-energy freeloaders-- over 13 years of $18/month electric bills. Our costs (largely DIY second-hand gear but including tax subsidies) paid themselves back within six years and we’ve just been reaping the benefits since then. Depending on the information source, the median Oahu electric bill is $150-$200/month.
https://www.electricitylocal.com/states/hawaii/
Of course the “free” solar energy changes your conservation behavior. We have about 3KW of elderly panels on our roof, and we rarely use more than we generate because we have an insulated roof & attics, a mostly insulated house with energy-efficient windows, and tradewind cooling (with ceiling fans). Meanwhile our neighbor installed a 7KW system so that he could run his air conditioning 24/7 in an uninsulated house. He simply no longer has to care.
The only place I've ever seen truly FIRM figures on pay-back for RE (NOT counting on the grid to do the heavy lifting and cost smoothing) is with solar HOT WATER installations. IMHO anyone who builds a new house in the Islands (and much of the southern US) and does NOT install SHW is making a huge mistake. It's the perfect solar. It has its own built-in storage so it works at night. The few times there isn't enough sun, one can tap the grid for "boost." One could actually skip the occasional daily shower (or shower with a friend, heh, heh.) The only significant down side is initial cost which could be smoothed with the mortgage or eased with gummint rebates. My thinking on RE is to pick the low hanging fruit first. Solar hot water makes sense NOW in almost any place that gets decent sun for most of the year. As always, YMMV.
Absolutely. Solar water heating is now Hawaii state law for new-construction homes. Paybacks are about eight years, or around three years with the state subsidy.
I haven’t turned on the electricity to our solar tank’s backup heater in over a decade. But then I do most of my showering at the beach after a two-hour salt-water bath.
I'm sure Nords knows the full story on this, but in Hawaii, the local electric utility HECO limits the amount of solar that can be tied into the grid (within specific areas, as I recall - maybe 10% max?) In any case, if there is a place that solar should work, I'd think it would be the Islands. So far, I'd say it probably works (financially) for some early adopters, but not for the state as a whole.
Here’s where we photovoltaic grid-tied freeloaders are doing society a favor: we’ve disrupted the energy monopoly.
Public utilities have few reasons to modernize (let alone innovate) because they’re essentially heavily-regulated non-profits. From their perspective, the most efficient distribution grid would be filled with centralized coal and natural-gas plants-- the more and bigger the better. The only load balancing requirements would be simple demand regulators and predictable customer behavior heuristics. You’d have hundred-year-old electric poles and 1960s transformer cans filled with PCBs.
The only thing the electric company would want to do would be to build bigger plants whenever the demands supported the capital expense. Sure, they’d have to repair a few components, but they’d only upgrade if the new widgets were dramatically cheaper and much more reliable.
Now the governments have let people connect cheap (subsidized) roof-mounted energy generators to the grid. On intermittently cloudy days, these generators rev up & down to randomly dump power into the grid. This makes it challenging to keep the bus voltage at a rock-steady 240v AC, which is why the amount of generation per neighborhood is limited.
Oahu started out at 100% PV grid penetration, measured by use. Simplistically, if a neighborhood had 1 MW of power consumption (from their electric bills) then it could add 1 MW of peak-power solar panels. (And as much solar water heating as they wanted.) Any additional PV panels might dump so much power into the grid that HECO couldn’t transfer it out quickly enough.
Then people started agitating for more PV power per neighborhood. Under customer demand (and govt scrutiny), HECO started getting questions about grid durability (hurricanes) and reliability (voltage control). If HECO wanted a rate increase ever again, they’d have to hide it among the grid upgrades.
Oahu is now moving toward 200% PV grid penetration, with plans to grow even more.
HECO is finally modernizing a grid which still has components older than me. Better yet, they’re not wasting their time planning (and funding) new coal or natural gas power plants. One day our grid will be much more able to handle power fluctuations, and it’ll be harder to take down the entire island with just one hurricane (or from a tiny earthquake under the generating plant).
HECO could've gotten away with an old grid, too, if it wasn’t for those durn meddling freeloader kids.
You’re welcome.
Now while we’re at it, let's think about buying electric vehicles and charging them from our PV panels for cheap local commuter cars. Maybe Hawaii could stop importing so much gasoline at >$3/gallon, too.
Thanks. My grandkids will be so proud of me.
