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If we didn't burn waste we'd need to burn something else to stay warm in winter. Currently we supplement the waste with _mostly_ renewables, like byproducts fro
by renhanxue 2y ago
If we didn't burn waste we'd need to burn something else to stay warm in winter. Currently we supplement the waste with _mostly_ renewables, like byproducts from the forestry industry (e.g. treetops, wood chips, sawdust) and the olive oil industry (olive pits; we import this stuff from the Mediterranean region), but we burn a bit of peat too because there aren't enough reasonably priced renewables. Burning waste really isn't meaningfully worse than burning anything else.
After the combustion we're left with 15-20% by weight in slag; some of this is metal that is recovered and sent to recycling, but the rest is effectively gravel that is used in e.g. road construction and the like. There's also 3-5% by weight of toxic gases captured by the exhaust gas treatment. This is sent to a special facility in Norway that more or less puts it in landfill, although a very carefully managed one.
- yreg 2y ago> If we didn't burn waste we'd need to burn something else to stay warm in winter. Why not nuclear/renewables?
- renhanxue 2y agoNuclear was a thing in the 50's/60's but district heating isn't practical over long distances and nobody wanted nuclear plants in their suburbs. Renewables we already do burn quite a bit of. But really, quite a lot of household waste is actually renewable too - cardboard packaging, food scraps that didn't end up in the compost, such things. So it's really not that bad. Waste accounts for about 20% of the total energy required for heating in Sweden.
- yreg 2y agoI meant what's impossible about making electricity from nuclear/renewable sources and then powering electric heaters with that electricity?
- eru 2y agoYou'd want to power heat pumps. Electric heaters get you 100% efficiency. Heat pumps get you 400%+ efficiency.
- renhanxue 2y agoThat is already a thing, and it's being expanded. The Stockholm municipal energy company is already operating what they claim to be the world's largest heat pump facility with a capacity to extract 225 MW of heat from treated wastewater. It first opened in 1986 and has been incrementally expanded over the years. Both the hot and the cold sides of the heat pumps are used; the cold side goes into the district cooling system and is used in e.g. datacenters. Still, this facility has both heat pumps, biofuel furnaces, and as a backup for the rare extremely cold days, resistive water heaters. It should also be mentioned that Swedish electricity generation is effectively 100% renewable already; it's mainly wind, hydro and nuclear. The co-generation plants mainly produce heating and only a small amount of electricity, more or less as a byproduct. Waste incineration has a more or less negligible carbon footprint if you look at the big picture.
- eru 2y ago> Nuclear was a thing in the 50's/60's but district heating isn't practical over long distances and nobody wanted nuclear plants in their suburbs. Modern heat pumps are really good (like 400%+ efficient), and run on electricity.
- toast0 2y agoPeople don't like it when you burn nuclear waste, burning windmills isn't very effective --- at least not the modern metal ones, and solar panels are going to be toxic if you burn them. :P
- sitkack 2y agoNeat, thanks!