Energy use in buildings: explain like I'm 5
October 14, 2019 2:58 AM   Subscribe

Why do we focus on reducing the energy demands produced by buildings (like heating and ventilation) if the energy still comes from nonrenewable sources with a high CO2 footprint? More below the fold:

I live in the EU and I see the energy efficiency regulations for buildings become stricter every 5 years, yet little is done to push for more renewable and green energy sources. Is this another instance where the responsibility is put on the consumer (in this case - the owner of a house) but not on energy companies? Isn't the real problem the fact that we are burning oil and gas? Or will we really offset global warming by applying 60 cm insulation the every wall? To me it seems a bit as if I'd go to a shop which uses plastic bags, but instead of coming up with a better, environmentally-friendly solution, they give me a smaller bag and charge extra for it.
Besides, when we introduce energy efficiency solutions, do we take into account the CO2 released by manufacturing this technology? One thing is insulation itself, but an airtight envelope calls for artificial ventilation, which calls for more devices, which increases the electricity consumption, and electricity isn't too green either. Do we look at the life cycle of the devices? As I understand, in low-energy consumption buildings the cost and CO2 footprint are offset after about 20-30 years, but do these technologies serve as long? Isn't it the case that micro-climate tech develops quickly and is replaced as quickly, without actually offsetting the real impact on our planet? In the meantime, despite all these technological innovations, we are still burning fossils and releasing CO2 into the atmosphere.
My knowledge is very limited, but I'd like to understand more about this issue, and all input is very welcome. If you can direct me to books, articles or research that deal with it, I'l be very grateful. So far when I'm trying to find a critical view on the approach to energy use in buildings (in EU or elsewhere), I usually end up reading about how global warming is not actually real, ugh.
Many thanks!
posted by luminary to Science & Nature (14 answers total) 2 users marked this as a favorite
The approach is multi prong - the building regulations impact you directly, but at the same time the EU is pouring money into renewables and tightening regulations on emissions from fossil fuels (eg by enforcing the CO2 emission permits regime). The impact from reducing fossil energy use by 10 MWh and replacing it with 10 MWh of renewable energy is the same - so if you do both it's double the benefit. With global warming as fast as it is, we can't afford not to do everything possible to slow it.

Quite frankly a lot of 20th century buildings are built in cost cutting cheap ways dependent on cheap fossil energy for heating and cooling. In some ways new regulations are going back to the way buildings were built before heating and cooling was this cheap.
posted by I claim sanctuary at 3:38 AM on October 14, 2019 [5 favorites]

These things are not all or nothing.

Consider lifetime energy requirements to run a building. Apartment and office buildings are used for decades. So reducing energy required to run them reduces energy demand for decades. It is in everybody’s interest to revisit minimum requirements for energy efficiency periodically and update them where that makes sense. And this building technology is subject to regular maintenance but full overhauls only happen infrequently, a couple of decades of use doesn’t seem unlikely although I am not in the business of property management.

Likewise the life of a power station is measured in decades. More and more renewable energy is being created and fed into the grid. As a result fossil energy production is used more and more to bridge any gaps between renewable generation and grid demand and to provide a buffer for peak demand. The big technological problem that remains is not renewable energy generation but storage of energy not required by the grid. The battery technology is not yet available to do this effectively and efficiently. So you can’t just switch off the traditional power stations completely.

What they can do and do do is support both renewable energy generation and the development of these technologies. And you can see the results of this. Global demand for traditional power generation is going down significantly, there is a lot less investment in new facilities even compared to five years ago. And these are massive infrastructure investments that cost hundreds of millions and take years to build, so there are time lags. And this isn’t just a decline in investment to increase capacity but also lower demand to replace existing fossil power generation with more fossil power generation.
posted by koahiatamadl at 4:03 AM on October 14, 2019 [1 favorite]

The impact from reducing fossil energy use by 10 MWh and replacing it with 10 MWh of renewable energy is the same - so if you do both it's double the benefit.

To put this another way: if we reduced the amount of energy we used worldwide by one-half, then we'd only have to build half the number of carbon-neutral power plants to replace existing fossil fuel power plants, and we get to a carbon-neutral economy that much faster.
posted by Johnny Assay at 4:17 AM on October 14, 2019 [8 favorites]

This isn't “either/or”, but “and”. Insulation and high-efficiency lighting is dirt cheap compared to building new power plants. The cheapest power plants are the ones you don't build, so by increasing user efficiency you can also shut down some old dirty power plants. People renovate or move much more frequently than power plants can be permitted and built, and small incremental improvements by millions of people can make a difference.

In my city, over half of the GHG emissions come from operating residential and commercial buildings. So it's reasonable that we focus efforts on fixing that.

To avoid the energy crank sites, start with national or international building standards (such as LEED) or building management organizations. All of them are addressing sustainability.
posted by scruss at 4:22 AM on October 14, 2019 [6 favorites]

Generally efficiency improvements are cheaper than adding capacity.
posted by pompomtom at 4:53 AM on October 14, 2019 [3 favorites]

Coal power stations are turned up in the UK to cover periods when our electricity generation is not met by renewable sources. Reducing waste through building improvements will reduce the number and duration of situations where those coal stations will need to be turned on.
posted by rum-soaked space hobo at 5:10 AM on October 14, 2019 [3 favorites]

The EU has a policy commitment to improve energy efficiency by 20% by 2020 and, as part of the same agreement, to hit a target of 20% of all energy (not just electricity) to come from renewables by 2020*. So every EU MS has policies in place to achieve both goals. However some member states have higher and some lower than these 20% figures, based on internal negotiation. UK targets are for 15% renewables for example, reflecting less progress at the time the targets were agreed, existing hydro, etc.

So all EU states are taking some action on renewables, what you see depends on which you live in. Some states have taken way more action. You can see progress in this 2019 document, with national figures on page 5.

(*The EU also now has a 2030 target of 32% of energy to come from renewables, improve EE by 32.5% by 2030.)
posted by biffa at 5:27 AM on October 14, 2019 [3 favorites]

Go grab a copy of Soft Energy Paths: Toward a Durable Peace by Amory Lovins, first published in 1977, and read it. Seriously, do. Many things will fall into place for you.

One of the main takeaways is that the best greenhouse gas emission reduction strategies are the ones that cost the least per ton of emissions reduced, and that simply removing the need for any given quantity of energy is almost always the least-cost option by far.

On the whole, increasing end-use energy efficiency to get the same end-user services from less energy is an emission reduction strategy that saves money rather than costing it, and doing that first means more money is available to put toward replacing fossil-fuel-based energy generation with renewables and storage.

End-use energy efficiency is the single biggest untapped energy resource on the planet today, and that's likely to remain true for decades to centuries.
posted by flabdablet at 6:25 AM on October 14, 2019 [4 favorites]

It's a very complicated question, because all the targets are moving very fast these days.
Regarding energy efficiency, the thinking behind it began during the energy crisis in 1973. Back then, the issue wasn't so much global warming or pollution, in spite of Limits to Growth being published in 1972. It was just a very basic understanding that we should use less fuel, because of the economy. At the time, America and the UK, and the East block still produced coal and for the US some oil, so the urgency wasn't felt as much as in Western Europe, that had some coal mines, but not enough, and the oil and gas extraction had only just begun. And on the other hand, the idea of saving energy was normal. Modernist architecture in post-war US had ignored energy efficiency, and that inspired modernizing Europeans to do the same, but reality was that fuel was rationed up into the fifties, and most people felt it was crazy to waste ressources on heating or air-condition. A lot of experience from pre-modern construction was still applied, for instance here, all homes have to be naturally cross-ventilated by law. So strict regulations on energy efficiency came naturally and were widely accepted. After all, for the average consumer the cost-savings were a positive effect. For the post-1973 architects, there was even a beauty to be found in the thick walls. They were reminded of traditional heavy masonry buildings, even though the thickness was now built of insulation, not bricks.
Then there came problems of ventilation you mention, but also worries about the sustainability of the materials used. Western Germany was a frontrunner on new ways of thinking this, specially in states and cities where the Greens were big. So many places in Europe, there is actually not a strict regulation on energy use if you can prove the energy comes from renewables. The Zollverein School is an example of this. Still, many buildings are just insulated towards a zero-energy ideal, like you say. After a generation of thinking in low energy use, I think most architects and engineers take it for granted that a building needs to be well insulated. But many use insulating glass instead of wall materials.
Right now, things are changing again. After 40+ years of development of low energy houses, the carbon-footprint of the construction process itself is beginning to equal or even surpass the use. So people are beginning to look at how to build with less energy use, and that is going to change a lot of things when the industry becomes confident enough that it makes it into regulation.
The reason regulation is important is that it levels the playing field. Right now, all buildings have to be energy efficient or provide renewable energy. That means that the costs of building are equal for all stakeholders. There is not yet a demand for sustainable construction process, so it is experimental and expensive. When the technology is out there, everyone will want to go there, and regulations will mean the costs are a given for all. But it isn't quite there yet.
I don't think you are right about the lack of push for greener energy sources. In the EU countries that have mines or oil and gas production, leaving fossil fuels is politically difficult because there are tens of thousands of jobs involved. But the EUP election clearly showed that the population want to go that way, and politicians all over Europe are reacting accordingly.
posted by mumimor at 7:17 AM on October 14, 2019 [5 favorites]

As a second data point - the California Energy Code uses a performance-based strategy to lower overall energy targets per building. Energy models are used to predict performance and certify a minimum standard of efficiency- this standard gets more stringent over time with the goal of universal net zero performance in 2040.
I can say with confidence that:
a) no developers and few homeowners or even government agencies would build the way that we are now without it being a code requirement. Energy efficiency is not high on the list of priorities and this is the only way to drive performance.
b) Technology often follows implementation. Many green technologies like high efficacy lighting and advanced insulation would not be as affordable as they are without the economies of scale that were created by code requirements. This is about pushing the industry to advance itself as much as anything else.
posted by q*ben at 8:26 AM on October 14, 2019 [4 favorites]

So far when I'm trying to find a critical view on the approach to energy use in buildings (in EU or elsewhere), I usually end up reading about how global warming is not actually real, ugh.

I think this is probably quite revealing. Fundamentally your question seems to be asking if it's possible to genuinely make buildings more energy efficient over their lifespan from construction. The reason that the only people saying you can't are cranks is because, yes, it is definitely possible to increase energy efficiency, and this can be done by way of regulation.
posted by howfar at 8:58 AM on October 14, 2019

Besides, when we introduce energy efficiency solutions, do we take into account the CO2 released by manufacturing this technology?

This is a very common and sensible question. Here's a very quick way to answer it. Let's say you are considering adding insulation to your house. Does this reduce net CO2?

The way to crudely estimate this is just the cost of the proposed improvement. The price you pay for installing the insulation includes all of the materials, all of the labor, the shipping and all of the energy used to produce the insulation. So if your heating energy bill is reduced over time by an amount at least equal to cost of the insulation, then it most certainly covers the energy used to produce the insulation.

So to a first approximation, to determine if the net CO2 is reduced, just consider if the proposed improvement saves you money in the long run.

This crude approximation doesn't always work, but it certainly works for a lot of the simpler energy improvement solutions people talk about.
posted by JackFlash at 10:50 AM on October 14, 2019 [4 favorites]

One other thing is an efficient building is generally more comfortable than one that is not. Less drafty; better humidity control; temperature swings take longer to go from min to max. Lighting is generally better (assuming competent design). Walls that have a higher level of insulation will tend to be closer to room temperature when faced with extremes of temperature outside so you'll feel more comfortable with lower(heat)/higher(A/C) thermostat set points. This last one is often over looked but is a huge advantage to radiant heat; especially in slab on grad construction. Having your floor warm will often allow setting the thermostat back 2-3C in a heating climate with no other changes.

High efficiency wall assemblies also attenuate sound better (for a given wall style) so noise levels inside are lower in noisy (urban) environments (and if you are running a table saw or your kid is screaming your neighbours won't be able to hear as much).

Those sorts of advantages are lost when we just throw operating energy at a building instead of making capital improvements to reduce operating costs.

And one of the easiest ways to score efficiency points when constructing a building is to design it to be climate appropriate. This is almost free and yet we see cookie cutter, fashionable and or cheap designs that are built with no consideration to the site they are being built on nor the climate of the area.

TL;DR: Efficient buildings are comfortable buildings.
posted by Mitheral at 9:29 PM on October 14, 2019 [3 favorites]

an airtight envelope calls for artificial ventilation, which calls for more devices, which increases the electricity consumption, and electricity isn't too green either.

Just to pick up on this one minor point: efficient insulation doesn't necessarily require an airtight envelope, because air-to-air heat exchangers are a thing. And even if the building design is poor enough that it does need forced air to ventilate it properly, just moving air uses a hell of a lot less energy than heating or cooling it as well.
posted by flabdablet at 1:20 AM on October 15, 2019 [2 favorites]

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