For a few decades now, going green to harness the power of the sun for your home’s electricity needs has meant adding solar panels to the roof or some other sun-drenched place on your property. We’ll call that Solar 1.0. Some designs I am aware of (mostly outside of Texas) have turned the solar panels vertical and clad the side of a structure with the blue-black panels. I’ll name that Solar 1.1. A European company that makes glass roofing tiles created their product to allow sunlight to penetrate into the attic space (Solar 1.2?) so that solar panels could be concealed and protected within the attic space.
Now forward to today, or really last week, at the start of November 2016 and we’ve maybe arrived at Solar 2.0? Unless you’ve been so tuned into the pending presidential election that you missed something interesting, you may know that Elon Musk (Tesla Motors, Space-X, Solar City) debuted a new solar roofing product by Solar City that they think may just be a game-changer.
Image from Tesla / Solar City
According to their website www.tesla.com/solar, the solar cells are hidden in the tiled roofing products. Their information says the tiled solar products will provide enough power for the average home (whatever that is, as at the time of this blog post average home sizes keep rising and so too do their levels of energy consumption) at a lower cost than traditional roofing when you factor in the projected energy savings. I’m all for that! I think.
The Solar City / Tesla solar tiles are reportedly due to hit the marketplace some time in 2017, and they are slated to come in four options that mimic the appearance of common, upscale roofing products. Except I don’t see an analog to the ever-popular standing-seam metal roofing which is appearing on more and more sloped roofs in the Dallas and Austin areas.
Image from Tesla / Solar City
In response to the undetermined sales price for the solar tiles, Consumer Reports undertook a short study with this article to find out what maximum price might make sense for the system which is comprised of the solar tiles and Tesla’s Powerwall2, a battery system to store electricity for nighttime use. They used a 3,000 sf roof as a baseline for the size of roof needed to cover the average US home. With a life-expectancy of 30 years, Consumer Reports estimated the savings from being off the utility grid and added that to the cost of standard roofing, and deducted the cost of the battery unit to determine a guess on how much could be charged for a solar roof and have it make some economic sense to the homeowner.
If you want to check out their data, head over to their article. I am curious about the application of these roofing tiles on my own roof, because when I costed out a regular solar panel system (yep, good old Version 1.0) it wasn’t a very viable option for my roof. My wife and I currently occupy a 1,925 sf home that requires about 3,200 sf of roofing material to re-roof the entire house. Seeing that figure add up makes me yearn for a flat roof…and feel for those of you with steeply pitched roofing that will have an even higher floor area-to-roof area factor (the factor increases as roof pitch goes up, meaning you need vastly more roofing material for a steeply pitched roof like many of my neighbors have vs. my 1980’s era 4-on-12 pitched roof).
Roofing materials are usually quantified and costed-out in number of squares required. A square of roofing is equal to 100 sf of material, but since it is on a pitch (as seen above) isn’t just the tally of your home’s square footage on the ground. My roof totals about 32 squares, and I’ll call it 33 for my calculations to allow for a little overage. A square of quality 30-year composition shingles will vary in cost due to labor but I will use $600/square for easy math, thus meaning a re-roof on my own house might be about $19,800. To mimic Consumer Reports’ method, I need to estimate how much I pay in electricity and multiply out for the next 30 years. Our house averages about 1,000 kW of usage each month, or 12,000 kW a year. If I’m paying 11.5 cents per kWh, that costs out to around $1,400 per year for my electricity usage.
In 30 years, the utility meter will tally up about $42,000 which is far lower than Tesla’s $60,000 worth of energy saved but my home is smaller than average, and we’re pretty efficient on our usage and easy on the thermostat. Subtract the $6,500 Powerwall2 battery which I’d just have to have, and my 30-year energy savings is $35,500 with the solar tile roof. Add the cost of re-roofing with more comp. shingles, and for us the solar tile roof shouldn’t cost more than $55,300. Yikes indeed! But remember, the promise is for 30 years of $0.00 utility bills. And like Solar 1.0, if your roof tiles generate more energy than you use, it gets fed back to the grid and the utility company might be paying you for the extra energy.
Now that I’ve bored you with all this number-crunching, just like with Solar 1.0 I’ll say if Tesla comes to market with a fairly competitive price structure, and if you’re going to be in your home for a very long time, then it could make some sense. Me? I’m not going to hold my breath for Solar 2.0 just yet…but I’ll likely not be in this house for another 30 years to make it all make sense.
This post was originally written before re-branding as Eckxstudio for Modern Architecture at the end of 2017.
At Eckxstudio for Modern Architecture, we design unique and stunning projects, individually crafted for our clients’ lives. We’re passionate about listening to your needs, wants and desires as inspiration to design the dream home you’ll never want to leave.