Want to go off-grid? You might need hundreds of Tesla batteries

Preface. Although you may not be as far north as Victoria, British Columbia (48.4 latitude), you’d ideally want to be at 30 degrees or less latitude from the equator to even consider the expense of off-grid solar power.  And even then you’ll need to be wealthy. Keep in mind that the Tesla Powerwall 2 is $5,500 for the battery alone, plus about $1500 additional charges for installation and other components.

If you’re getting solar for when TSHTF, you’d better have a lot of spare parts and enough mechanical bent to fix the system yourself until the batteries die…

 — Alice Friedemann   www.energyskeptic.com  author of “When Trucks Stop Running: Energy and the Future of Transportation”, 2015, Springer and “Crunch! Whole Grain Artisan Chips and Crackers”. Podcasts: Derrick Jensen, Practical Prepping, KunstlerCast 253, KunstlerCast278, Peak Prosperity , XX2 report


November 23, 2017. Want to go off-grid? You might need hundreds of Tesla batteries.The Climate Examiner, Pacific Institute for Climate Solutions.

Going completely off-grid is infeasible for most households in Western Canada, energy systems modellers conclude, due to the diminished amount of sun in our northern latitude. To “cut the cables” to the electricity grid, requires an impractical number of batteries or solar panels.

Note that:

  • The scenarios below do not account for electricity needs to heat homes or charge electric vehicles
  • Fewer solar panels = you need more batteries
  • Fewer batteries = you need more solar panels

Families in BC use solar panels on their roof and install batteries in their garage because they want to reduce electricity costs or do their part to help reduce emissions. Some have dreams of one day going entirely off-grid. So researchers with the Pacific Institute for Climate Solutions’ 2060 energy future pathways project modeled just how feasible this would be.

They used 2016 data from a typical three-bedroom house in Victoria with an annual load—or average electricity demand—of 9,600 kilowatt hour (kWh). The house uses natural gas for its heating and a conventional gasoline vehicle, meaning no extra load from these sources.

A common PV system is 12 kilowatts (kW) as a larger PV system requires more roof. Researchers found that given Victoria’s solar irradiance, a 12 kW PV system needs a 1,766 kWh battery to achieve self-sufficiency. This is equivalent to 131 Tesla Powerwalls.

Another option is to reduce the size of battery and buy a larger PV system, as more energy is available and thus less needs to be stored. If a homeowner bought a 30-kW PV system, they could get away with a 289 kWh battery (equivalent to 21 Powerwalls). But this PV system would require an area of roughly 300 square meters (3,200 square feet)—about the size of a tennis court.

They ran the numbers for Vancouver, Kelowna and Calgary. The results for Vancouver and Kelowna similar to Victoria. But Calgary, with its clearer winters, required less PV and battery capacity to be self-sufficient. Calgarians could make do with a 9 kW PV system and about 62 Powerwalls. With a 30 kW PV system, taking up 240 m2 (2,475 square feet), the homeowner needs roughly 10 Powerwalls.

But in these clear, cold places, the electricity demand of the household rises due to the electrification of heating and transport so the prospect of self-sufficiency is even further out of reach. The researchers found that the increase in demand from heating via electric baseboards at least a 22 kW PV system and 236 Powerwalls. Newer technologies, such as heat pumps would have a reduced impact on electricity demand.

The projections for the number of batteries seem mind-boggling, but they are in line with storage requirement assessments for other jurisdictions.

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11 Responses to Want to go off-grid? You might need hundreds of Tesla batteries

  1. Rob says:

    Living in Alberta at 57 degrees north we get a bunch of solar for most of the spring through to fall. The very short, very low sunshine of the winter is a deal breaker. There is no way to get enough solar, you have to be either grid tied or genset makeup.

  2. Joe Clarkson says:

    Wow! 26 kWh per day for a ‘typical’ house is indeed a lot of electricity use to supply with solar PV.

    I doubt that a house designed to use PV as its only electrical supply would use but a tiny fraction of 26 kWh. With passive solar or wood heat, a high efficiency refrigerator and LED lighting, I bet electricity use could come in under 5 kWh per day. Then add a small fossil backup generator for extended gloomy days and the PV system could be quite affordable.

    On the other hand, British Columbia gets 85% of its electricity from hydro, so why would anyone there need to go solar?

    • Rob Charles says:

      I concur with your surprise at 26 kWh of electricity consumption per day – this high usage is only possible in a household with no concern about energy consumption and the environmental consequences of such wasteful energy usage.
      After implementing a variety of electricity-conserving measures (including most of those you suggested), my 1800 sq ft house in Toronto (at 45 degrees latitude) with its 4 residents has averaged less than 4 kWh of electricity consumption per day over the past 5 years. And no, we are not “freezing in the dark”, and we have all of the usual household appliances; we are just careful.
      Our rooftop 2 kW PV system, albeit grid-tied such that the grid is our battery, generates annually almost twice as much electricity as our household consumes. Based upon the current number of km we drive annually (less than 8000 km), our “surplus” PV production would be sufficient to charge an electric vehicle (we don’t own one yet).
      Furthermore, our rooftop solar water heating system supplies about 80% of our annual household hot water needs.
      Although detractors can argue correctly that we are not truly energy self-sufficient every day of the year, we are close, and if other households chose a similar approach, future global energy supply and environmental concerns would be minimized.
      What has surprised me, and the other residents of my household, is just how easy it has been for us to achieve this low level of energy consumption while maintaining a very high level of comfort.

      • energyskeptic says:

        The problem as I describe it in my book “When Trucks Stop Running”, is that rail, ships, and the heavy-duty trucks that do 90% of the work all run on diesel fuel. Oil is not used to generate electricity, so all the wind, solar, and hydro in the world doesn’t help in using less oil. Oil also makes everything else possible, including renewables. But maybe when things fall apart on the other side of the oil curve, you’ll live better than your neighbors for a while.

  3. Hugh Conway says:

    Not true. We are off-grid and have been so for 5 years. Coastal (cloudy) location at 50degrees N latitude. We have a normal sized home, not specifically designed or built for off-grid use and use about 2kwh daily. Solar panels rated at about 2100w. A generator is necessary for about 4 months out of the year to top up old style lead acid batteries. That is due in part to low sun angle and obscuring trees on both sides of winter solstice. Fuel usage is about 1 1/2 liters a day when the generator is required.
    The key is to reduce electrical consumption. Practice energy conservation before going off grid. It was an easy transition.

    • energyskeptic says:

      But as I replied to someone else, perhaps only 5% of Americans can install solar systems because the distribution of wealth makes it impossible for most people, and many wealthy people live in high-rises and buildings, they don’t have the roof space. I have friends with solar in the San Francisco Bay area at 38 north, and for half the year they have to suck in grid electricity, and the other half barely break even because of fog and how far north we are.

  4. red says:

    I live in a 1300 sqft home at about 44 degrees north. The home is “off grid” 5.4 kw pv. We have a dishwasher and the fridge has an ice maker. the Hot water is demand gas fired and the stove and dryer are as well. We use wood fire for heat and as such we burn less than two cords of wood per year. Gas consumption is about 700 litres per year. The battery bank is 8 200 amp hour lead acid. The inverter is an Outback 8kw 240vac. The whole system cost $24,000.00 Canadian. We have a gas fired generator as back up. We’ve been off grid for 11 years and so far the only issue has been a replacement battery bank, the cost of which,(approx. $3000.00) was figured in at the start. I don’t have a meter to be able to give you our daily electrical demand but going in I’ve calculated it at around 4kwh. We do our laundry and run the dish washer on sunny afternoons and have been stumbling along nicely. I would never go back to the grid as we watch the power outages happen more often due in part to increased weather severity. I suspect the lack of preventative maintenance in order to pay higher dividends has as much to do with that as the deteriorating weather. The problem with the calculations that are done for articles such as the above is it is always done for the way power is used in existing situations. Efficiency has to be taken into account if this is to work. Mostly the only take away I get from such articles is the amount of waste that is considered “normal”. If you were to run an on grid home as we do the fee the power company charges for reading the meter would be the biggest part of the bill. Convenience=waste. Laziness really, why should anything be inconvenient. Less energy required to run your life = less money needed = less time at a daily job = more time at home. What kind of slave are you?

    • energyskeptic says:

      Your system may make your life better, but 90% of Americans and 99% of the rest of the world don’t have $24,000 Canadian, In America, 58% would have a hard time getting their hands on $1,000. Only a small percent of Americans have a fireplace and forests near enough to get wood from, and in a crisis, it wouldn’t take long to cut forests down. At some point in the energy crisis, people will be on their own to craft parts and fix their solar and other systems, as long as batteries last that is.

      My concern with wasting energy and money on renewable systems is that they can’t possibly keep society going, as is well documented at energyskeptic with peer-reviewed studies — and common sense — renewables depend on fossil fuels in every single step of their life cycle. We’d be better off converting industrial agricultural farms to organic agriculture, funding energy efficiency projects like insulation, and a million other things.

      But hey, it’s a rewarding lifestyle, and congratulations for getting off the grid in lovely Canada!

      • Mark says:


        I just noticed that Stanford competed, awhile back, a major project to reduce the carbon footprint of the central power station and campus as noted here- https://news.stanford.edu/features/2015/sesi/

        “..”Also key to SESI is the new, on-campus Central Energy Facility (CEF) that relies on a heat-recovery process that is 70 percent more efficient than the cogeneration process Stanford used since 1987. The CEF will meet more than 90 percent of campus heating demands by capturing almost two-thirds of the waste heat generated by the campus cooling system to produce hot water for the heating system. To make that exchange possible, Stanford has replaced 22 miles of underground pipes and retrofitted 155 buildings to convert the campus from a steam- to hot-water-based system.”

        By chance have you seen any independent evaluations of this project?

        • energyskeptic says:

          Although I referred to smaller scale efforts in this post, I am most concerned about the long term impact of the decline of fossil fuels on all of civilization, I can’t see any way to maintain it at this level without fossil fuels, especially oil, which is what this whole site is about. I’m glad that Stanford has reduced their energy use, if only society as a whole would, or could afford to do so. To prepare for the future we should be massively install and build well-insulated homes, drop the speed limit to 55 mph, and a million other things, but we’re going full-speed ahead into the brick wall.

  5. Rob Charles says:

    Re: The Affordability of Solar Systems

    It is good to hear about others who have resisted the easy route of head-in-the-sand complacency commonly accompanied by blind faith in technology, and in the economists and politicians, to “save us” from the looming doom and gloom.

    Admittedly, a single household going off-grid or in our case achieving “net zero” energy consumption while embracing conservation and renewable energy has insignificant impact on global energy demand, but it sure beats sitting on your hands waiting for the apocalypse. Furthermore, each household decision to conserve and switch to renewables influences other households to follow a similar path.

    Yes, the manufacture of renewable energy systems uses fossil fuels, but I would argue that this use of fossil fuels provides a superior energy return (EROI) compared to burning the fossil fuels directly to generate electricity.

    And yes, $24,000 is a lot to pay to go off-grid, and as energyskeptic points out, surveys and statistical analyses indicate that the majority of Americans (and I assume Canadians as well) have $1000 or less in actual savings, which would seem to make it obvious that most cannot afford to invest in a household PV system. But as Mark Twain, and others, were fond of saying: there are lies, damned lies, and statistics. In other words, one can use selected statistics to “prove” almost anything.

    So here is a hypothetical statistical exercise to “prove” that a Cdn$24,000 / US$19,200 PV system is indeed affordable for at least a significant percentage of American and Canadian households.

    Fact 1: the current population of the USA is about327 million; the current population of Canada is about 37 million; for a total of 364 million
    Fact 2: the average household in the USA and Canada comprises 2.5 individuals; i.e. there are about146 million households in the USA and Canada
    Fact 3: from 2013 to 2017 in the USA + Canada there were approximately 84 + 9 = 93 million new light vehicles sold of which about 5% were fleet sales; i.e. a 5 year total of 93 minus 5% or almost 90 million new vehicles purchased by individuals
    Fact 4: the average cost of these new vehicles was about US$35,000 (2017 statistic, slightly less in preceding years)
    Calculated Fact 5: an estimated 15% of households bought more than one new vehicle during the 2013 to 2017 period, such that 90 minus 15% equals over 76 million households, representing over one-half (52% to be precise) of all 146 million American and Canadian households, who were able to afford to spend an average of close to US$35,000 to buy at least one new vehicle

    Conclusion: Therefore, one can conclude that in the past 5 years more than one-half of American and Canadian households could have chosen to spend just US$19,200 (Cdn$24,000) on a PV system, rather than purchase a new vehicle at US$35,000.
    In other words, the 52% of households that purchased a new vehicle during the past 5 years, instead could have chosen to purchase a solar system and as a bonus would likely be financially further ahead having done so.

    Note 1:
    Of course I realize that these statistics also “lie” since they use averages; the average household only exists in statistics – all households are of course unique.
    Note 2 – The Case of our Household:
    • Our household income is now, and has been for at least the past 17 years, below average.
    • We purchased our PV and solar hot water systems for about Cdn$25,000 (US$20,000) in 2008 using a home equity line of credit. (Note that to date the downtime and maintenance and repair costs for our solar systems have totalled exactly zero. Of course, nothing works forever, so we know that eventually there will be costs, but the first 10 years have been happily problem-free.)
    • Our current vehicle is a 1995 station wagon, which in 2017 we drove just over 6000 km, since living in Toronto we walk or bicycle or use public transit most of the time.
    • Hence, despite our below average income, we chose to purchase solar systems for our house which were in fact significantly cheaper than purchasing a new vehicle.

    Overall Conclusion: Solar systems are affordable for the majority of households in the USA and Canada.
    It is primarily a matter of priorities.

    (My comments are mainly a response to the article above, as well as the comments of others, and thus focus on the feasibility and affordability of an off-grid or “net zero” home. But of course, as energyskeptic asserts, the primary global energy predicament is the almost total dependency we have on diesel and other petroleum fuels and products. This is a much more formidable challenge. Localization, among other big changes, will be necessary to address our current just-in-time, petroleum-based, globalized economic system if we have any hope of emerging from the downside of the energy curve with the best of our civilization still intact.)