For me, the thought of using the sun’s asphalt-melting energy to power my air-conditioned cocoon, light up my big screen and chill my beer is a dream right up there with putting a human colony on Mars. Unfortunately, for the last several decades, photovoltaic (PV) solar power hasn’t been economically feasible for single-family homes, and thermal solar power is only workable in larger-scale plants such as the one in Ivanpah just south of Primm.
But advances in the efficiency of PV solar-technology production and manufacturing have gradually put rooftop solar within budgetary range. So I recently set out to find answers to some elusive questions. For instance: Would going solar make me energy independent? How much would it cost? And, most importantly, how many beers could I chill at once?
First, some general info about Standalone PV solar power systems: They’re actually pretty simple. Panel modules mounted on your roof convert available sunlight into a 12-volt DC power stream, similar to that produced by a car battery. That power is then converted to standard household 120-volt AC power by an inverter that’s connected to your home’s electrical system. Because power stops flowing at night or on cloudy days, a standalone system also requires batteries.
Now, I’m not a Doomsday Prepper, nor am I particularly motivated to drastically alter my lifestyle to address climate change. Really, I am fine with the almost 12-cents-per-kilowatt-hour, uninterrupted supply of electricity provided by NVEnergy. But I am curious if going solar would help reduce my annual $1,500 in electric bills. How much would it run me to cut the NVEnergy cord and generate my own beer-cooling power?
I ran a quick calculation for my 2,600-square-foot Henderson home using numbers from August, when I burned through 1,634 kilowatt hours, the most of any month in 2014. My low-usage winter months require an average of only 500 kilowatt hours. But if I didn’t want to cut back on energy consumption in the summer months and wanted to generate and store 100 percent of my power using PV solar, I would need to generate nine kilowatts of peak power on demand to make it through those triple-digit days that chain smoke their way through July and August. I wouldn’t need most of that power for most of the year, but again, in this scenario I would be “off the grid” and totally reliant on solar power generated solely on my property. This puts my solar requirement for the year at the high end of residential, off-grid units. My cost for such a system (not including shipping, racking or installation): nearly $30,000, if I ordered off the shelf.
But that $30,000 price tag doesn’t include maintenance costs. Solar systems are generally considered extremely reliable; power-cell modules are normally warrantied for 20 years, over which time power production falls off slowly. However, inverters—widely considered the weak link in the solar chain—are only warrantied for five years. Even with good luck, I would almost certainly have to shell out the $8,000 it would cost to replace it at least once before the solar panels required replacing. That pushes the 20-year cost of my system (without installation) to $38,000—the equivalent of 25 years of paying my current NV Energy bill. Without compromising my current energy usage, it’s clear that shifting to solar under these circumstances wouldn’t make economic sense.
Then again, few people who rely on solar power for their homes ever completely detach from the grid—that’s a radical move normally reserved for cabins, survivalists’ bunkers or anywhere there is no available public utility. Most suburban solar homeowners remain connected to the existing major utility infrastructure, pulling power the old-fashioned way when their PV system can’t keep up—such as at night, on cloudy days or, in Vegas, pretty much any day in July or August.
Staying connected eliminates the need for battery storage and means you can buy a system that takes care of your average use. In such instances, NV Energy uses “net metering” to give you credit on your bill for the power your panels generate. That credit helps offset the cost of pulling power from the grid when your energy demand is high and your panels can’t keep up.
But PV equipment and installation still isn’t cheap, even with federal tax incentives and local-utility rebate programs. Most solar installation companies offer financing as well as something called power-purchase agreements, in which they install panels on your home but retain ownership and sell you the power generated by their panels at a predictable rate—a rate that’s not particularly enticing. For example, at SolarCity—the biggest solar outfit in the Valley—the 20-year fixed power-purchase agreement runs 13 cents per kilowatt hour while NVEnergy is currently charging me 11.6 cents per kilowatt hour. Translation: Solar still isn’t making much sense to me.
To try to penetrate the cost confusion, Solar-Estimate.org, an unaffiliated consumer and solar trade information site, offers an online estimator that uses the Department of Energy’s PVWatts software tools to generate a rough cost-benefit analysis. The calculator takes into account currently available local and federal tax incentive and rebate programs, but makes no guarantees about the continuing availability or applicability of those programs to your situation.
For my home, Solar-Estimator came in at an installed cost of $34,000 before incentives, if I wanted to stick with a nine-kilowatt net-metered system. Incentives bring the purchase cost down to about $22,000, which is nearly identical to buying electricity straight from the grid. On the other hand, if I went with generating only 50 percent of my peak power, I would cover most of the months of the year and cut my after-incentives cost to $14,000. A leasing option was estimated to cost about $150 a month for the 100 percent system and $93 a month for the 50 percent system. But in the latter case I would still be buying at least half my power from NV Energy, so my monthly bill from them would ramp up.
To see if I was hitting at least close to actual costs, I called SolarCity. Their phone-quote numbers came in about the same as the online solar estimator.
Given that my average electric bill is $125 a month, the only reason I would go through the headache of vetting bids, wading through contracts and ultimately installing a solar power system would be to do my bit for the environment. To quote the SolarCity sales rep: “You’re not going to get rich off of it, but it can help a little.”
Frankly, I just want to keep my beer cold.