How a sand battery could transform clean energy

[oldbrownhat]

I think the title is a bit optimistic, but you gotta give those young Finns credit for thinking outside the (sand) box. With more development perhaps it could be a useful addition to other technologies, where there is an abundance of solar and/or wind energy during the day.

A new way of storing renewable energy is providing clean heat through the long Nordic nights.

BBC article here

"...The challenge is how to provide a year-round, steady power supply from renewable energy during changing seasons and variable weather conditions. The answer nestling in Vatajankoski power plant, 270 km (168 miles) north-west of Finland's capital, Helsinki, is remarkably simple, abundant and cheap: sand.

The Vatajankoski power plant is home to the world's first commercial-scale sand battery. Fully enclosed in a 7m (23ft)-high steel container, the battery consists of 100 tonnes of low-grade builders' sand, two district heating pipes and a fan. The sand becomes a battery after it is heated up to 600C using electricity generated by wind turbines and solar panels in Finland, brought by Vatajankoski, the owners of the power plant.

The renewable energy powers a resistance heater which heats up the air inside the sand. Inside the battery, this hot air is circulated by a fan around the sand through heat exchange pipes...."​

 

[delcrossv]

A heat sink. Interesting, but I wonder what the energy density of it is.

 

[oldbrownhat]

A heat sink. Interesting, but I wonder what the energy density of it is.

Good question. The article only states:

There are of course limitations, experts note. "A sand battery stores five to 10 times less energy [per unit volume] than traditional chemical batteries," says Dan Gladwin from the department of electronic and electrical engineering at the University of Sheffield in the UK..."
​

Their website might have some more info. At this point it seems the lack of emissions and long-term durability and simplicity is its main advantage, where there is sufficient solar/wind energy to "charge" the system. They are using it for district heating, much like steam is in some cities. If that could be incorporated into other urban environments it could perhaps be useful for heating some commercial buildings as well. It's certainly an interesting concept.

The biggest problem with some of these technologies is making them economical enough to warrant the investment. For instance, I have read that it is possible to use wastewater (sewage) to create biogas as an alternative/adjunct to NG, but the cost of building the infrastructure to extract it may not often be practical, plus offending the purists who insist on eliminating burning any kind of gas.

We are indeed "living in interesting times"

 

[SMSgt]

I've got a carburetor that gets 100 MPG, but none of the auto manufacturers will buy it.

 

[delcrossv]

Good question. The article only states:

There are of course limitations, experts note. "A sand battery stores five to 10 times less energy [per unit volume] than traditional chemical batteries," says Dan Gladwin from the department of electronic and electrical engineering at the University of Sheffield in the UK..."​

Not very dense then. About 40Wh/l

...

The biggest problem with some of these technologies is making them economical enough to warrant the investment. For instance, I have read that it is possible to use wastewater (sewage) to create biogas as an alternative/adjunct to NG, but the cost of building the infrastructure to extract it may not often be practical, plus offending the purists who insist on eliminating burning any kind of gas.

We are indeed "living in interesting times"

Exactly. Overcoming the intermittency of renewables, while trying to make sense economically, has been their Achilles heel from the beginning.

Interesting, but not ready for prime time.​

 

[Ivan the Butcher]

Houses with heat sink storage designed have been in the US and Canada since the 70's that I know of, and probably before that!

They are reinventing the wheel!

Ivan

Look up "Envelope Houses"

 

[oldbrownhat]

Houses with heat sink storage designed have been in the US and Canada since the 70's that I know of, and probably before that!

They are reinventing the wheel!

Ivan

Look up "Envelope Houses"

I remember reading about solar gain/heat sink houses several years ago. Another variation on the theme is the Trombe wall. I've also read of people heating (tempering) south-facing greenhouses by lining the (solid, insulated) back wall with 45-gallon plastic drums filled with water which are heated by the sun during the day and release heat at night. Seems to work in certain climates where there is an abundance of winter sun.

Not quite the same thing as what the Finns are doing: super-heating an insulated bed of sand using resistance heating driven from solar and wind-generated electricity, then distributing the heat to houses via pipes buried in the sand. As delcrossy commented, "not ready for prime time", but might work in some environments. Good business for the manufacturers of insulation, too! I can see the stock value of Roxul and Knauf going up...

 

[DWalt]

There is no shortage of methods floating around to store energy from surplus generation capacity of “green” electricity (solar, wind, hydro). One of the more promising of them at present is using it to produce Hydrogen by water electrolysis, storing it, and using it to generate electricity in fuel cells when and where needed. It works, but is very expensive. There are several exchange-traded mutual funds (ETFs) that invest in the stocks of smaller companies attempting to capitalize on the development of new or improved energy storage methods, but at least so far, their financial performance as investments has been dismal. Such companies exist mainly because they are heavily financed by state and federal grant money and tax incentives.The recently passed “Inflation Reduction Act” is loaded with funding that will be thrown away in prodigious amounts on such projects. Unfortunately, most seem more like chasing mysterious hidden buried treasure than anything else. Just like Oak Island. There is no cheap and simple way to overcome the restrictions of the laws of thermodynamics.

Investment tip of the day - Graphite.

 

[WR Moore]

The book I ordered on heating with wood finally showed up after the house and chimney was built. I'd have had the fireplace done much differently if it'd shown up when it was supposed to.

At any rate, there was one method shown that was interesting, but might not have worked for our layout. One builds a massive stone fireplace/chimney in the middle of the house (OK to move it?) and a relatively small air tight firebox heats the stones. The stones then radiate the heat for hours. IIRC, you fired it twice a day.

 

[BigBoy99]

Isn't Geothermal heating the same thing?

 

[oldbrownhat]

...at any rate, there was one method shown that was interesting, but might not have worked for our layout. One builds a massive stone fireplace/chimney in the middle of the house (OK to move it?) and a relatively small air tight firebox heats the stones. The stones then radiate the heat for hours. IIRC, you fired it twice a day.

That's the Tulikivi soapstone fireplace (again from those Finns), or similar designs using massive masonry. They're not cheap, especially in soapstone, but they burn very cleanly and can be a real work of art. Probably the ultimate wood burner.

Similar designs have been used in northern Europe and the Baltics for ages and re also known as a "kachelofen."

There is no cheap and simple way to overcome the restrictions of the laws of thermodynamics.

As a famous playwright wrote a few hundred years ago, "Aye, there's the rub."

 

[DWalt]

Isn't Geothermal heating the same thing?

No. That involves tapping into the Earth’s natural heat from far underground, not storage of surplus generated renewable energy. Depending on location, it can get very hot the deeper you go. Most of Iceland’s energy needs is derived from geothermal sources. That is the ultimate green energy.

 

[bigwheelzip]

Our town hall on Long Island stored off-peak electric power as thermal energy for AC. Basically they had an insulated thermos tank the size of a car, which was filled with water that they refrigerated to ice, then used the ice as an AC heatsink.

Sent from my motorola one 5G using Tapatalk

 

[oldbrownhat]

No. That involves tapping into the Earth’s natural heat from far underground, not storage of surplus generated renewable energy. Depending on location, it can get very hot the deeper you go. Most of Iceland’s energy needs is derived from geothermal sources. That is the ultimate green energy.

"Geothermal" is also used (correctly or not) in reference to earth-air heat pumps, which are becoming very popular as they are very efficient and provide both heat and cooling. Downside is the cost of installation due to having to either dig a long trench for the piping, or drilling down. Air-air are somewhat less efficient and not as good in colder temps, but are cheaper and are improving as they develop better refrigerants. (One member here, "docmurgow"??) says they are using the latter in Vermont, which is encouraging.

 

[Beemerguy53]

...One builds a massive stone fireplace/chimney in the middle of the house (OK to move it?) and a relatively small air tight firebox heats the stones. The stones then radiate the heat for hours. IIRC, you fired it twice a day.

Friends of mine in Germany built their home with heated floors. They have a pellet fuel furnace that circulates hot water through a network of tubes underneath the hardwood first floor. The warm floor then evenly heats the entire house. It works very well...

(Btw...they live in a village south of Munich, in the foothills of the Alps, and don't have or need air conditioning.)

 

[oldbrownhat]

Friends of mine in Germany built their home with heated floors. They have a pellet fuel furnace that circulates hot water through a network of tubes underneath the hardwood first floor. The warm floor then evenly heats the entire house. It works very well...

(Btw...they live in a village south of Munich, in the foothills of the Alps, and don't have or need air conditioning.)

Biomass boilers are quite popular in Europe. Viessmann is one of the main suppliers. Ironically, here in BC, where we have lots and lots of wood, several years ago pellet manufacturing facilities sprung up (and I bought a pellet stove), but recently they were bought out by a British company that ships most of our pellets to Europe. The pellets I get here are either from Alberta or Québec.

 

[arjay]

Have a wall of stone with a fireplace in this place that I added sealed glass doors to. Build a fire at dusk,keep it going til 9 and that old tech will radiate heat until early morning

 

[Golddollar]

The Vatajankoski power plant is home to the world's first commercial-scale sand battery. Fully enclosed in a 7m (23ft)-high steel container, the battery consists of 100 tonnes of low-grade builders' sand, two district heating pipes and a fan. The sand becomes a battery after it is heated up to 600C using electricity generated by wind turbines and solar panels in Finland, brought by Vatajankoski, the owners of the power plant.

The renewable energy powers a resistance heater which heats up the air inside the sand. Inside the battery, this hot air is circulated by a fan around the sand through heat exchange pipes...."[/INDENT]

Would we soon have sand huggers yelling "Save the Beaches?" It would be interesting to see them handcuff themselves to a pile of sand.

 

[delcrossv]

No. That involves tapping into the Earth’s natural heat from far underground, not storage of surplus generated renewable energy. Depending on location, it can get very hot the deeper you go. Most of Iceland’s energy needs is derived from geothermal sources. That is the ultimate green energy.

Lots of dissolved radionuclides in that steam. Conveniently overlooked.

If a US nuclear plant had the same external dose, it'd be shut down by the NRC.

 

[venomballistics]

Not too far off from geothermal in overall principal.