The 'Sand Battery' that heats your home, NOT the planet!

i'm making this video right in the middle of the second heatwave of the 2022 british summer season continental europe is suffering droughts and water shortages as well and i know you folks across the pond are also experiencing record-breaking heatwaves this summer with well over 100 million of you sweltering in temperatures above 38 celsius or 100 degrees fahrenheit in the last few weeks so it might seem a bit inappropriate for me to start banging on about the desperately urgent need to find more efficient lower carbon waste to provide heat for our homes because right now they're warm enough thank you very much but of course time marches relentlessly on and the northern hemisphere winter will be here soon enough current world events are showing many others just how hopelessly dependent we still are on fossil fuels and how crippling the price hikes are likely to be as supply lines become ever more restricted according to recent polling most people seem to agree that we need to move rapidly away from fossil fuel heating but the question is what are we going to move to and if we're apparently going to be relying on 100 renewable energy in the future how are we going to guarantee constant heating during the cold dark months of winter hello and welcome to just have a think arguably the first thing to consider when you're looking at how to heat buildings with low or zero carbon technologies is whether to install small individual units for each building like a heat pump for example or to provide a single large solution like a district heating network for an entire town or city we don't have that kind of district infrastructure here in the uk and there aren't many examples over the states either but district heating is pretty popular in scandinavia eastern europe and china and there's a good chance as brits and you americans could see them becoming more commonplace on our shores in the decades to come the big challenge for the operators of these systems today is how best to move away from the fossil fuels that currently provide the majority of the energy and one of the potential solutions to that problem is thermal energy storage no doubt many of you will have seen recent media coverage of this thermal energy storage system built by a finnish company called polar night energy which is now being operated in the city of kankanpar by a district heating provider called vatijankowski i caught up with polar night energy's chief technical officer and vati yankovsky's managing director via zoom recently to find out more about how the system works essentially it's an energy storage unit that works as a closed air loop heat exchange system inside this 4 meter diameter silo is 100 metric tons of nothing more exotic than bog standard sand from a local supplier a couple of kilometers down the road air is heated up externally to about 600 degrees celsius by an electrical resistance heater and fed through a system of pipes that circulate through the sand in a very specific configuration which gets the center of the sand extremely hot indeed while keeping the outer sections much cooler that's quite a smart feature which has the effect of minimizing the amount of extra internal insulation needed to stop the heat from radiating out into the atmosphere that reduces the overall size of the silo and of course it keeps the costs down too once the sand is at full temperature it can store that heat for several weeks or even months with very minimal thermal losses and then when the district heating system calls for heat it's a simple matter of running ambient air back through those same pipes and hey presto hot air comes out the other end that hot air gets diverted into a standard air-to-water heat exchanger which is then fed straight into the district heating system this particular installation in kankanpar is capable of discharging heating power of 100 kilowatts constantly for 80 hours which means it has an 8 megawatt hour energy capacity that's more than three full days and nights of constant heat going into the district heating network polonite's chief technical officer marco ilonan pointed out that while it would be technically feasible to configure a system that discharged over a much longer period of weeks or even a month or two the size cost and technical challenges involved in building and running a configuration like that just wouldn't make it economically viable in any kind of storage system fewer cycles always means a more challenging economic model and anyway as marco explained there's really no need for such an extremely long duration discharge period to avert the use of fossil fuels at least known finland anyway winter brings far more reliable high winds than the summertime so the proportion of wind power on the finished grid tends to be higher during the winter months and of course one of the many advantages of energy storage is that the operator can choose when they want to put that energy back in fatty yankowski's pekka passi explained that wind power already makes up about 10 percent of the finnish power system and more wind farms are coming online all the time and actually if we look at the global situation courtesy of this chart from the u.s pacific northwest national laboratory we can see that around two-thirds of all new global power generation capacity added each year now comes from wind and solar the global fossil fuel energy situation and in particular the restriction of gas from russia has inevitably had an effect on prices of everything in the nordic energy market but even so pekka says there are still certain times during the week when the price of electricity gets close to zero at night time there's always a lot of fluctuation in the price of electricity on the wholesale market and that's likely to increase as intermittent renewable energy sources play a greater role in the mix that means it'll become ever more important to have flexible energy storage solutions so that cheap electricity can be utilized when it's available the optimum operational level that polar night energy are aiming for is somewhere between 20 and 50 cycles a year which corresponds to roughly 100 hours for each charge and 100 hours for each discharge this relatively small system is serving a useful dual purpose for both companies firstly it's proving the concept in a real-world setting something that the beam counters quite rightly need to assess before they start splashing millions of euros on a new technology and secondly it just so happens that this system is a perfect size to enable vatijankovsky to make use of otherwise wasted heat from their own data center right now about a third of vatijankoski's energy comes from industrial waste heat and about two-thirds are derived from burning wood-based biomass fuels as a major district heating supplier the company's mission is to end the combustion of biomass in their system within 10 to 15 years partly to meet ever tightening decarbonisation targets but also because the combustion of carbon fuels will simply become so expensive in future that it'll no longer make economic sense the waste heat from the data servers at their power plant site gets to about 60 degrees celsius which is not hot enough to be used in a district heating system it really needs to be above 75 degrees they could have used heat pumps to bump the temperature up but when they looked at the sand battery they realized it offered them a lot of storage capacity in a small space and they really wanted to test out its potential this current system is big enough to supplement all of the waste heat from the data center but also small enough to minimise the initial capex exposure for vatijankovsky and at four meters in diameter by seven meters tall polar night energy were able to fabricate the whole thing off site and transport it by road to its final destination but the real fun starts at scale up the medium-term plan for polar night energy is to produce gigawatt-hour energy systems with about 15 megawatts of discharge power that size is a good fit for the majority of district heating networks and also for all sorts of different industries that require process heat or high pressure steam for their operations a system that size would cost around six to eight million euros to supply and install which corresponds to somewhere between six and eight euros per kilowatt hour of installed capacity a one gigawatt-hour storage cylinder would have a diameter of around 20 meters and it'd stand about 10 meters high which is big but actually not at all unusual in an industrial setting in fact by sheer coincidence almost at the same time as polar knight were installing their pilot system the swedish utility giant vatenfall began filling up a 45 meter high storage tank in berlin germany with 56 million litres of water to store heat at 98 degrees celsius when it comes online in 2023 this enormous cylinder will have a maximum thermal output of 200 megawatts which will be discharged directly into the local district heating system for up to 13 hours at the time equating to an energy capacity of 2.6 gigawatt hours imagine what that capacity would be if it was filled with sand at 500 degrees celsius these sort of relatively simple thermal energy storage solutions use cheap off-the-shelf components and abundant storage materials like sand or water but also gravel crushed rock metal pellets or molten salts all of which are readily available and which present little or no environmental risk they sit right up towards the top end of the long duration storage solutions and they can be deployed more or less anywhere which gives them a significant edge over other options like compressed air and pumped hydro they typically last for decades with minimal degradation unlike lithium-ion batteries which lose a little bit of capacity with every charge and discharge cycle and when these facilities are used to provide direct heat rather than converting heat to electricity they can be as much as 95 efficient heating for buildings and process heat for industry accounts for about 50 of the total global energy demand most of that still comes from fossil fuels so thermal energy storage solutions like these look set to play a key role in the global decarbonisation effort that the intergovernmental panel on climate change tellers will be vital if we're to stand any chance of keeping global temperatures down to only 2 degrees celsius above pre-industrial levels so what's your view on this sort of system do you have district heating where you live and if so how well do you think a thermal energy storage solution would fit into your local network maybe you work in the industry and you can share a bit of insight on the latest progress if you do or if you've got other news and views on the subject then why not jump down to the comment section below and leave your thoughts there that's it for this week though a massive thank you as always to our amazing patreon supporters who keep these videos completely independent and ad free and if you feel like you could support the channel for about the price of a coffee each month via patreon and keep me producing and publishing these videos each week then you can find out how to do just that by visiting patreon.com forward slash just have a think and of course the easiest way you can support the channel via youtube is by clicking that subscribe button and hitting the notification bell it's completely free and easy to do you just need to click on the little icon in the corner there or on that icon there as always thanks very much for watching have a great week and remember to just have a think see you next week

Channel: Just Have a Think

Views: 252,917

Keywords: polar night energy storage, vaajakoski power plant, vaajakoski polar night energy, vaajakoski sand battery, thermal energy storage system, thermal energy storage for solar heating and cooling, thermal energy storage explained, thermal energy storage methods, thermal energy storage tank

Id: sol9FOaKTr0

Length: 11min 28sec (688 seconds)

Published: Sun Aug 21 2022