What Could Possibly Go Wrong?
As I write this the news headlines are all power outages and deaths caused
by those outages (all a result of unanticipated weather conditions). Murphy
is once again right – “Anything that can go wrong will go wrong, and at
the worst possible time.” It’s Christmas, the coldest weather in 50 years
sweeps across, the power grid goes down in various States from Texas
to Maine – heat pumps, all electric devices (not battery powered),
even gas-powered furnaces controlled by electricity all go
down.
NOW – here is the question: Does it make more sense to spend your
money on the latest hi-tech or on additional insulation when designing
and building your house? It’s actually difficult to find many scenarios
where better insulation is likely to fail!
GBA Detail Library
A collection of one thousand construction details organized by climate and house part
Replies
It's a false dichotomy if we live in the north. Adding more and better insulation can't be done WITHOUT ALSO relying on high-tech powered gizmos to help us actually survive in that cozy shell--the ventilation, fenestration, lighting, and heating that our lifestyles require. A lot of this can't be done passively. But yeah, resiliency is a top-of-mind concern for most of us here, and this bomb cyclone exposes one set of weaknesses.
That's maybe a bit over the top. We don't have "power grids" going down, we have some regional outages, mostly on fairly small scales (by power grid standards anyway). Most of the deaths have been due to traffic too.
Planning for a power outage isn't a bad idea though. I don't really think extra insulation is the way to do this though -- doubling the insulation will get you something less than twice the time to drop a fixed number of degrees. The reason for that "something less" is because things like doors and windows contribute to heat loss too, and extra insulation in walls and ceilings won't help there. The problem is that all that extra insulate just buys you some time, usually only some number of hours -- maybe up to 10-12 hours or so. Unless you're starting with a *very* leaky/poorly insulated home, you're not going to be able to add enough insulation to gain you enough time to ride through multi day power outages without getting very uncomfortably cold inside your home.
If you want to plan for long outages, a generator is the best option. You can use a permanently installed unit, which is safest and simplest, or use a transfer switch and what is known as a power 'inlet', a special connected on the outside of the home, which will allow you to safely and simply connect a portable generator when you need it. You don't need a particularly large generator to run the essentials if you have some type of combustion heating system (natural gas, propane, oil). Heat pumps need more, but they're still manageable for larger portable generators, and are no problem at all for permanently installed generators that tend to be larger capacity (usually 12+ kw or so).
Note that solar isn't usually capable of running in what is known as 'island' mode without a grid connection, so if you lose utility power, you typically lose your grid tied solar system too. Going with an off-grid setup is way too much extra stuff to install and maintain if you just want backup power for outages. Some battery systems can help here, but they tend to be limited in runtime too (maybe a day or so at most with typical loads).
The reality is that long term utility outages are a problem regardless of how you heat your home, so they aren't necassarily more of a problem for an all-electric home compared with a home that uses natural gas for heat. Either system needs electricity to run, and about the only practical difference when putting in a backup system is that an all electric home will typically need a larger generator -- which will cost more to install (but not a lot more), and about the same maintenance costs over it's lifetime.
BTW, you don't need any fancy electronics to live in a better insulated home when the power goes out. All you need is an operable window. Crack open that window and you get some natural ventilation when you have no power to run your HRV. No big deal. You're not really in any worse shape in terms of thermal performance either, at least compared to a less well insulated home, because that less well insulated home is loosing more heat due to less insulation anyway -- your cracked open window hurts your performance somewhat, but doesn't mean you're in a worse position compared to the less well insulated home.
Bill
"It’s actually difficult to find many scenarios
where better insulation is likely to fail!"
The scenario I can think of is a storm blows the roof off of your house.
Insulation is a form of insurance, but not the best. Either real insurance, or something cheap and effective is a better way. A quality sleeping bag seems better than going from an R-60 attic to anything else.
A small generator and a wood burning stove will get you through any power outage for a normally sized home. As an added bonus, a gas fired oven/stove is handy too. Even a camping stove would work.
We went 11 days without power after Sandy. The biggest hurdle was finding gas to feed the generator and we live 30 miles from NYC!
Everybody who lives in a house should have some sort of backup. It's not all that difficult to figure out.
We live in NY too. After Sandy, we installed gas kitchen stove (for cooking during power outages), gas fireplace that works on battery operated remote (no electricity required) and direct vent water heater that doesn’t require electricity to run. So at least we have a source of heat and can cook and shower during power outages. We considered the generator but not sure if we really need it at this point.
Where we live in Maine, occasionally the power goes out for longer than several hours. Without a generator, everything in the fridge and freezer would spoil. And with a well, without power for the pump, we can't take a shower or flush a toilet.
We were without power from Friday noon until dinner time on Saturday. Since we were having a bunch of people for dinner on Saturday, I figured we might as well see what will run on our 7000 watt Honda gasoline generator. In the past, we've operated two minisplits without any issues, even leaving well pump and the usual household circuits on. The minisplits are on 15 amp/240 volt circuits.
So, I shut off the minisplits and the Heat Pump Water Heater and turned on the electric oven. Happily, it didn't trip either the 30 amp breaker the generator is connected to the panel with, or anything else.
We were pretty happy that we could operate every appliance, even though not all at the same time.
A typical electric oven is around 5,000 watts. I usually tell people that a ~7kW generator is something of a sweet spot for running a house mostly normally (some basic care to ensure the generator isn't overloaded), while maximizing fuel economy. A 12-15kw generator is good to keep a typically house running normally with NO concerns over overloading the generator. In my own home, the highest load I've ever gotten to on my 18kw genset is about 2/3 of capacity, around 13-14kw or so. That was with the air conditioner going, the oven, random lights, and some other things in the kitchen.
Glad your system worked out for you!
Bill
It's not just cold weather! I'm willing to bet that nearly everybody remembers the
pleas and begging by utilities (and politicians) during really hot weather to turn off
or limit the use of air conditioners - this has been endemic for decades now - often
in the same States that are suffering from the cold.
A little competent engineering design coupled with a lot of insulation goes a long way
toward preventing suffering by the individual - often turns it into a minor inconvenience.
Insulation doesn't often fail - the same cannot be said for hi-tech solutions, - remember
Murphy!! Insulation is relatively inexpensive - the hi-tech solutions, not so much.
Last, I note that there is always some push by utilities (and some politicians) to force
you to pay for their power grid (no matter how unreliable) even if you have managed
to find a way to generate your own - I think passive is the only sensible way - All Hail Murphy!
I'm not sure if people in other states appreciate just how bad our utility system is here in Maine. Our biggest provider is consistently ranked the worst in the US, even behind California's Pacific Gas and Electric that has regular brown-outs, and our second-largest utility is among the worst in the US as well. (https://www.mainebiz.biz/article/cmp-versant-rank-among-the-countrys-worst-utilities-for-customer-satisfaction) Because our state is sparsely populated, heavily forested and has shallow soil, large swaths of our population lose power in even modest storms. I was surprised to have made it through the most recent storm without fully losing power, though it flickered several times.
I have a portable 7kW gas-powered generator that provides enough power in emergencies. But I wish I had (and will eventually have) a better-insulated and air-sealed home; houses here that have Passive House performance will never freeze, and even most Pretty Good Houses will never freeze, even in extended power outages like the one in 1998 that left people without power for 2+ weeks.
My recommendation for resilience, at least in more rural northern areas, is: a good building envelope, a generator and a wood stove.
Are your outages more due to crummy maintenance (a common problem with many utilities), or very long runs of lines to very remote customers? I've sometimes seen issues where the problem isn't so much the utility not doing their job as it is just that the utility serves a particularly difficult area. We did here in my area, years ago, have an issue where the utility was going a bit overboard in terms of deferring maintenance (saving money gets you promoted! yay!), which then caused some massive outages for large numbers of customers (fines from the state PSC, not so yay...). They've been on a massive system upgrade campaign for the past decade or so since.
Are you *sure* that even a PGH house won't *ever* freeze over a week+ outage with no heat? With no heat, temperatures inside are going to gradually drop down to equilibrium with the outdoors, unless you have something fancy like some solar gain or other way to get a least some amount of heat in. My thinking has always been that insulation will "buy you time", but won't *prevent* problems from happening at some point, assuming it stays cold outside, during lengthy outages.
I do completely agree that going beyond code minimum with insulation, and especially paying attention to air sealing, is a really good way to greatly improve your home's resilience here. You also have the added benefits of saving money on heating ALL the time, and having a more comfy home too. I think a generator is probably the best/easiest way to allow for survival through essentially unlimited duration power outages though. I do that in my own home, and I'm in what I'd call a "semirural" area -- minimum 5 acre lots, lots of woods and water, long runs of lines, etc.
Bill
Bill, our utility issues are across the board--poor maintenance, outdated equipment, long runs to rural neighbors, etc.. Exacerbated by our frequent ice storms and nor'easters. The utilities are owned by overseas companies; there is a movement for citizens to buy it back but of course there is resistance among those wary of state-owned anything. Our PUC is stocked with industry veterans and appears to be toothless, if not outright corrupt.
I was careful to say that MOST PGHs would never freeze. Perhaps I should have used more qualifiers. I have seen Passive Houses here survive 10 days with no power with the outdoor temps never breaking 20°F, and I've modeled PGHs with no heating supply to see what would happen to the indoor temperature. PGH is about a lot more than insulation levels; good solar orientation and thoughtful window design and layout are also PGH principles, so there will always be some solar gain--even on cloudy days. Of course there will be exceptions, but 200 Btu/person/hr and solar gain can go a long way.
Michael,
Many buildings here in coastal BC had pipes frozen and were cold and uncomfortable - all because people typically under-build for whatever climate they are in.
Even with a good utility there will always be some areas prone to problems. I htink BC Hydro is excellent but an average winter sees us with 20 power outages. We had 8 over two days last week - and that is just in the 15 kms distance between us and the hydro dam that generates our electricity.
" a good building envelope, a generator and a wood stove." Here too.
All I have is a good building envelope and sun. Of course the latter doesn't alway work, but it's pretty good in Colo. My backup plan is the campervan. I don't think my house would ever freeze unless we had a truly nuclear winter event. I have uninsulated ground under the crawl space (possibly a mistake), so that would be a heat source if it got really bad.
We were our of town in mid Dec when we did see 3 nights at around 0F . The heat kicked on a few times to keep the house at 52. With 4.4 kw of solar we were net+ everyday even with the cold and very little sun a a few of the days.
Our grid is so reliable here it's hard to justify spending money for backup, but if I did anything it would be more technology, add battery backup to our grid tie system.