Geothermal ground source heat pumps. Heating your home from your own back yard!

if you caught our last video about geothermal heat energy you'll know there's an awful lot of it right under our feet in the earth's crust the challenge is to get at it in a safe environmentally friendly and economic way so as to produce a large-scale transfer of heat into a liquid then turns into vapor and moves across a turbine to drive an electrical generator which in turn provides extra power for national electricity grids and many of you who watch that video quite rightly pointed out that large centralized power stations like these aren't the only way to utilize geothermal energy for over two decades now systems have been in operation that allow individual homes and offices to produce their own micro generated energy from the very patch of land that surrounds the building the system is called a geothermal heat pump but you've probably more often heard it referred to as a ground source heat pump i think it's fair to say that the industry has been kept quite low key over the years and take up has been relatively slow in some parts of the world largely due to the perception of high upfront costs but the outlook is now changing fast just like pretty much everything else in these unprecedented times we're all living through the international energy agency found that almost 20 million households around the world purchased a heat pump in 2019 and according to analysis by consultancy firm global market insights worldwide sales are set to exceed 68 billion dollars by 2026 and you and i could be benefiting from a 40 to 50 percent saving on our home heating costs plus a hefty government subsidy depending on where you live so is it a good idea how does it all work and how can we all get a slice of this particular green energy pie hello welcome to just everything energy use in buildings accounts for more than 17 of all global greenhouse gas emissions and in somewhere like the united states between 50 and 70 of all energy used in the home goes on heating and cooling different fossil fuels are used to heat and cool buildings in different parts of the world many countries rely heavily on gas but oil-fired heaters are also still in widespread use the one constant that can be relied on in every part of the world though is the fact that the temperature of the ground directly below us is far more stable than the temperature of the air around us which is subject to all the vagaries of the ever more extreme weather conditions that means it's generally cooler than ambient air during the hottest days of summer and warmer than ambient air during the colder months and that basic fundamental physical property is what makes ground source heat pumps such a simple and effective solution here's how they work a mix of cold water and antifreeze is pumped through a ground array of energy absorbing pipes getting constantly warmed by the ground's low grade heat as it circulates the warmed up mixture then gets fed into a heat exchanger otherwise known as an evaporator where it transfers its energy to a secondary fluid with a much lower boiling point and that fluid then turns to a gas which gets compressed to increase its temperature still further the hot gas then flows into a condenser where it dumps its energy into a space heating system or even to provide the hot water for the building if required once all that energy has been transferred out of the gas it turns back into a liquid and goes through an expansion valve at the end of the cycle to reduce its pressure and temperature back to the starting point it's a completely closed loop cycle so the fluid just goes round and round absorbing energy from below and dumping it where it's needed not all homes and buildings have huge expansions of space around them of course in those cases rather than winding the energy absorbing pipes around in a horizontal array about a meter underground they can be sunk about 100 meters vertically downwards like this system being installed by a company called ngo out in california for each kilowatt of energy consumed by the system four kilowatts of heat energy are generated effectively reducing the cost per kilowatt hour by 75 percent in hotter countries that normally use air conditioners during the summer time the stable ground temperature will actually be lower than the hot summer air and that means the whole cycle can be reversed so the excess heat from the ambient air in the building can be transferred into the system and sent back through the cycle to be dumped into the ground via the pipe arrays turning a heating system into a very efficient cooling system saving between 20 and 40 percent on the electricity bill for a traditional air conditioner in most cases the ground source heat pump is combined with a more traditional water boiler to ensure there's no risk of the home lacking heat during extreme weather events but even if that boiler is heated by fossil fuel there is still a large reduction in co2 emissions over the lifetime of the installation because the vast majority of the work is done by the heat pump at most times of the year and better still if the fossil fuel boiler is replaced with an electric boiler fed by a renewable energy tariff then those co2 emissions are even more drastically reduced which of course is the main object of the exercise up in sweden where the northernmost regions are actually inside the arctic circle geothermal heat pumps have become a standard alternative to district heating in many buildings as the owners have found that installing and running their own setup is actually cheaper than paying the cost of the communal system according to the swedish department of geology in 2016 there were more than 300 000 domestic geothermal heat pump systems in use across the country most of them used that combination of the ground source heat pump and backup boiler running on grid electricity that i mentioned earlier one of the early challenges of this setup was the demand on the grid during peak usage periods you see to optimize cost versus efficacy the heat pumps were generally dimensioned to provide about half the power demand which actually equates to about 90 percent of the energy use but during very cold days which are not uncommon in sweden these combination systems were using three to four times more power per degree as the heat pumps reached maximum power and the electric boilers were kicking in and that was causing a very unwelcome spike in demand on the national grid but new heat pump systems are now fitted with very smart inverter technology which can handle full power heating demand and that simple addition has resulted in lower energy bills for the consumer less marginal electricity demand and greater available capacity on the grid for distribution to other energy users all in all a much more sustainable solution it's well worth checking out robert llewellyn's excellent recent video over at the fully charged channel looking at moonstone house in the uk which generates more energy than it uses and is actually fitted with both horizontal and vertical geothermal heat pump systems according to this article by molly lemprier published on the current news website in september 2020 here in the uk while decarbonization of electricity has steamed ahead it seems heat has often been forgotten the sector generates about 37 percent of total uk carbon emissions when you add in industrial processes so olympia argues that now is the time for action if the countries to hit its net zero target by 2050 but while the technology is now mature and well proven governments have not been willing to provide the sorts of subsidies and grants that are really needed to kickstart the transition for most individual domestic consumers the power of the fossil fuel lobby is still extremely strong despite the economic kicking they've endured during the lockdown period globally that industry still receives hundreds of billions of dollars in subsidies and tax breaks to keep their products looking competitive against established and now cheaper renewable alternatives like solar and wind and they exert great influence on lawmakers to keep renewable incentives to a minimum despite that there was a glimmer of hope in august 2020 when the uk chancellor rishi sunak announced the introduction of the green home grants a two billion pound fund to drive home improvements amongst other technologies this includes heat pumps with the government covering up to two-thirds of the cost for six hundred thousand households the green homes grant is an upfront payment but it's capped at five thousand pounds which doesn't go a very long way towards the cost of a well installed ground source heat pump system there's also a parallel uk scheme called the domestic renewables heat incentive the rhi is designed to help those who install eligible technologies claim back the majority of the cost of the installation over a seven year period but if you claim both incentives the domestic renewable heat incentive is reduced by the amount of the green home grant to prevent what the government calls double funding the details of eligibility and applicable rates are pretty complicated so to help with navigating the small print i contacted the company that installed the solar power system on my home back in 2017 they're called iso energy and they're the uk's most experienced consultants and installers of renewable energy systems i asked them to run through some numbers based on my fairly typical three-bedroom victorian terraced house with a garden out the back first and foremost i so advise that a horizontal system isn't suitable for a small garden like mine so they base their numbers on a borehole installation a nine kilowatt system including the cost of drilling the boreholes all the internal componentry and a full-size hot water storage tank from first survey to full installation and commissioning comes in at about 26 thousand pounds a retrofit here in the uk has reduced vat rates of five percent instead of the normal twenty percent so we still need to add another thirteen hundred on to that to take the total to just over twenty seven thousand but i also explained that the domestic renewable heat incentive can earn the owner of a system like this as much as four thousand pounds a year for the seven years so you're looking at a payback time of about seven years which is actually slightly quicker than the payback on the solar power system that i've had since 2017. the obstacle of course is that the homeowner has to pay for the system up front and claim back the incentives afterwards and not many of us have got the best part of 30 grand kicking around for a rainy day these sorts of incentives will obviously vary depending on whereabouts in the world you live but the technology has been embraced in almost every corner of the globe in hot climates and in cold climates because of its remarkable ability to maintain a stable ambient interior climate by effectively equalizing air and ground temperatures the challenge as always with paradigm shifting technologies like this is the cost of investment in infrastructure and as usual we find ourselves with the eternal triangle of public perception commercial caution and government leadership these three things can either be a self-reinforcing mechanism or a precarious house of cards if the right level of government incentive is put in place then consumers will see the value of converting that'll entice more investment into the sector which will increase competition and drive down prices which in turn will attract more and more people to purchase the systems and so on and so on sounds a bit obvious when you say out loud doesn't it but it's not happening quickly enough at the moment and it needs to accelerate fast if withstand any chance of meeting the united nations target of global carbon neutrality by 2050. if you've got views on this one or of course if you have any direct experience of installing and running one of these systems then dive down to the description box below and share your thoughts there that's it for this week thanks to one of our channel patrons bjorn johnson for providing some of the research information for today's video particularly around the swedish example and of course to iso energy for their help with the uk cost examples do have a quick look at the website and the app if you haven't already done so and i must just give a shout out to some new supporters of the channel who've joined our patreon page since last time with pledges of 10 or more a month they are robert knowles paul raggett kate evans mike franklin michael bellarata daryl mckinnon tony dobson andreas down mitch rundle gordon johnson michael baker and eric kroger and of course big thank you to everyone else who's joined since last time too you can support the channel at our patreon page where you can also exchange contacts and ideas with other patrons get exclusive monthly news 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Channel: Just Have a Think

Views: 225,918

Keywords: geothermal energy, gorund source heat pump, renewable energy, climate change, climate emergency

Id: 1jCHYUuEDZ8

Length: 13min 35sec (815 seconds)

Published: Sun Oct 04 2020