Heat Pumps: How cold rivers could heat your home

Heating our homes with cold water! Sounds absurd? It’s not. Heat pumps are revolutionizing the way we heat and cool our homes and cities. We went to the German city of Mannheim to find out how.

#planeta #heatpumps #energy

We’re destroying our environment at an alarming rate. But it doesn’t need to be this way. Our new channel Planet A explores the shift towards an eco-friendly world — and challenges our ideas about what dealing with climate change means. We look at the big and the small: What we can do and how the system needs to change. Every Friday we’ll take a truly global look at how to get us out of this mess.

Credits:
Reporter: Tim Schauenburg
Camera: Simon Baingo
Editor: Frederik Willmann
Superivising Editors: Joanna Gottschalk, Michael Trobridge

Read more:
IEA: The future of heat pump globally:
https://iea.blob.core.windows.net/assets/4713780d-c0ae-4686-8c9b-29e782452695/TheFutureofHeatPumps.pdf

Heat pumps potential in Germany:
https://static.agora-energiewende.de/fileadmin/Projekte/2022/2022-04_DE_Scaling_up_heat_pumps/2022_Scaling_up_heat_pumps_in_Germany.pdf

Fraunhofer IEG: On large scale heat pumps in Germany:
https://www.ieg.fraunhofer.de/content/dam/ieg/deutsch/dokumente/ver%C3%B6ffentlichungen/Rollout_Grosswaermepumpen_Angora_Fraunhofer%20IEG.pdf

Chapters:
00:00 Introduction
00:43 What’s the problem?
01:04 What my ice bath has to do with heating
01:37 Heat from the river
02:08 This is how it works
04:32 It all started with a fridge
05:40 Substituting coal, oil and gas?
06:30 Environmental risks
08:46 Smaller units and the money question
10:32 Conclusion

Being a climate journalist is never all laughs, but this? Ok, lets do it! I’m doing this for you! This is beyond next level! I want to show you how to heat entire neighourhoods with water as cold as this! It’s like a thousand of needles in my legs. The answer – with a heat pump.

A very big one. But even the small ones are indispensable when it comes to de-carbonising housing. These gadgets can convert seemingly infinite amounts of energy from the environment to warm our homes – even in winter. But how is that done and why aren’t they everywhere yet? Nothing requires more energy worldwide

Than keeping houses warm and providing heat to industry. Heating accounts for half of the global energy consumption. And 72% of our heating comes from burning fossil fuels. Long story short: To limit global warming, we need to bring heating emissions down. But before we get to that, we need some cold facts. I mean, really cold.

Ok, I’m not ready at all. Oh, god. It’s -1 degrees Celsius outside, and the water is only slightly warmer. Thank you, Planet A! Why am I doing this again? It’s unbelievable but here in the city of Mannheim in South-West Germany, this ice-cold water is used to heat thousands of homes!

We are going to find out how this is possible! Mannheim is a mid-sized city of about 300,000 inhabitants. It sits directly on Germany’s biggest river, the Rhine. And you guessed right, the river plays a key role in this story. The magic is happening in this. The local energy provider is producing electricity and heating

Through a mix of fossil fuels and cold water. Until today, the region relied heavily on the most climate-harming source for heating: coal. This is Felix Hack. He’s Energy Manager at energy company MVV, the magic-machine we’re about to show you is his baby. This single power plant is responsible for

About 6.8 million tons of CO2 every year. That’s almost 1 percent of Germany’s annual emissions. But this is changing for the better, right now. So this deafening giant is in fact a heat pump for rivers. By pushing through 800 liters of river water per second, it can provide heat for 3500 households all year around.

Ok, wait a second! Let’s take a step back! This is what happens in all those pipes: The water seem cold to us, but it’s easily warm enough to turn a liquid refrigerant into gas, as this can evaporate at extremely low temperatures. The gas expands. An electric pump then compresses this gas. This generates heat.

It’s a bit like with a bicycle pump. The longer you pump, so the higher the pressure, the hotter it gets. Try it out! The heated gas is used to warm up water or air, for example. The refrigerant gives up its heat and becomes liquid again – and the process can restart.

This mechanism is so efficient, you can generate 3 times as much heat with the same energy as with a gas boiler. It doesn’t just work with river water, you get the same effect with heat from air and the ground. Ideally, the electricity for the pump comes from renewable energies.

But even if it comes from fossil fuels, it’s still more sustainable. The principle of a heat pump isn’t new at all. It’s based on a concept which has existed for a very long time, and on a technology which most of us have at home. A refrigerator! Back in the 19th century the demand for cooling

Was much higher than for heating. Ice was carried from far away as there was no possibility to keep things cold. In 1859, the Frenchman Ferdinand Carré designed the first commercially successful ammonia absorption cooling system. It works the same way as a heat pump but the other way around, carrying heat from inside to outside.

From there, another familiar machine evolved. The air conditioner: invented to solve hot air and humidity problems in the printing industry. Only later, the heat pump had its big moment. “The pride and joy of the man of the house is the weather control center. A center that puts you in charge of the electric heating

And air conditioning and the electronic air filtering of the entire house.” With Western economies booming after World War II, bringing widespread electrification and new lifestyle expectations, heat pumps fitted right in. But as most people were happy to burn cheap oil and gas for decades, they didn’t really catch on – until now.

So, now we are going to see the heat storage from where the heat is being distributed over the entire city. At the moment by far the largest proportion of this is still heated with coal. Only 3 percent of the heat comes from the river. But that will soon change,

As the coal-fired power station will probably be shut down by 2033. As energy-efficient and sustainable a river heat pump is, taking heat from the river means, that the water is being discharged 3 degrees colder after the process. With potentially negative impacts on a larger scale. “Luckily, at the moment most of our waters are overheated

Due to climate change. So it’s beneficial to a point. And beyond that you will have an adverse ecological effect that you might want to avoid.” This is Fabian Ahrendts, scientist at Germany’s Fraunhofer IEG and expert for large-scale heat pumps. However, due to the small quantities of water being discharged,

The temperature in the river only changes by less than one ten-thousandth of a degree, according to MVV. “But now imagine all along the river Rhine, all the major cities are there, wanting to cover their entire heat demand, including industrial plants such as the BASF or Covestro plants right along the river Rhine

That all might use water for heat pumps for their processes. And suddenly you get, you get an issue.” Another issue are the refrigerants. They can be terrible greenhouse gases. Watch our video on F-gases if you want to know more. There are alternatives on the market, which have less global warming potential.

But some have other issues such as being easy to ignite and manufacturers tend to produce business as usual. In Mannheim, the generated heat is distributed via district heating over and underground. In Germany, around 15% of all buildings are now heated in this way.

And most of it could be met by large heat pumps, cutting out coal and gas. They are still a niche but installations have started to pick up. A role model is the Swedish capital Stockholm where about 90.000 apartments are heated from wastewater. And the Norwegian city of Drammen

Provides most of the heat for its 65.000 residents with heat from its cold sea water. And communities don’t even need district heating. Heat pumps can be directly attached to a building or industrial site where temperatures up to 200 degrees Celsius are needed. Heat pumps can extract energy from almost anything:

Air, wastewater, steam and even from the ground. And they don’t need to be huge They can be pretty small too. and be used in almost any residential building, like this one. By 2030, heat pumps could save as many emissions as all cars in Europe produce per year.

With smaller units taking a central stage. Especially as heat pumps can also turn from heating into cooling mode. and are more energy-efficient than classic air conditioners. But there is a catch. Of course, it’s the money! “Particularly when we’re installing our first heat pump, switching from a different heating system

Is always going to be more expensive than we are right now.” This is Louise Sunderland, she’s a policy expert at non-profit Regulatory Assistance Project. She has a heat pump herself and loves it. Right now, in 2024, heat pumps can cost two to four times more than natural gas boilers.

It’s a big outlay, especially for low-income families. On the other hand, long-term they could save you money as heat pumps need less energy. In Europe, households currently save on average $900 per year and in the U.S. $300. But the advantage over fossil fuel heating depends highly on… jepp, energy prices.

“Before the recent energy price crisis, when prices became unpredictable and volatile, on average across Europe, electricity was around 3, 3.3 times more expensive than gas. So you can see if you’re having an efficient heat pump, getting a 300%, 400% efficiency, you might be saving some money there.

In the UK where I live, before the price crisis, electricity was five times more expensive than gas. So you can see there that you would really struggle to be saving some money.” So if heat pumps are more sustainable and economically viable depends highly on your government’s energy policies

Whether they favour cheap green electricity over fossil fuels. In Mannheim, the prospect of high CO2 taxes, local climate targets and state subsidies for the construction of the plant were decisive in the switch to river heating. Their target is to provide almost 100% clean heat by 2030.

The heat pump won’t cover all of that, but will be one important component to eventually shut down the dirty coal power plant behind me in the near future. No matter if small or large scale: heat pumps are more sustainable and can make regions more independent from fossil fuels.

And they do work in winter, I hope you appreciate the effort I put into showing that! I can’t say I can enjoy it. Are heat pumps popular where you live? Let us know in the comments, subscribe to our channel and hit the like button. We have new videos for you every Friday.

And I need to get out of here now! Alright. I made it!