Will microwave boilers ever replace gas?

[fronty]

Hi all, I was reading about these new microwave boilers that are due to come out from Heatwayv (A new way to transform how we heat our homes | Heat Wayv - https://www.heatwayv.com/), they seem to be a drop-in replacement for your old gas boiler, but with electrickery costing about 5 times as much per kwh as gas, how on earth are we going to be able to afford to run them? Are they designed to use less energy? I don't understand how that works, ie if you need a certain amount of kwh to heat your DHW/CH circuits, surely it doesn't matter if the fuel is gas or electric. So how are we going to be able to afford to run these, the economics don't seem to stack up unless the government is going to subsidise electricity (highly doubtful)?

 

[snowhead]

Their claim of no new gas boilers to be installed after 2030 is not only a LITTLE bit economic with the truth it's also unachievable.

The Microwave boiler will just be another option available,.

They fail to speak anything of running costs comparisons and untill their forthcoming mass trials they won't be able to make any claims on costs.
They make no mention as to whether the National (Electric) Grid would be able to cope or whether properties would need an upgraded electrical supply.

 

[Last Plumber]

The infrastructure for everything electric is not there!

I think the whole subject is fueled by media frenzy and the powers that be need to stop and re-think things for a while.

 

[snowhead]

Found this from the Guardian;

The Heat Wayv unit is the same size as a gas boiler and has 10 metres of pipe coiled inside, which is heated at multiple points along its length. The microwaves are produced by solid state components, which can be tuned specifically to heat water and better targeted than the magnetrons used in microwave ovens.

The electricity load will be about the same as an electric oven, the makers say. They say the boiler is 84% efficient in converting electricity into hot water, and another 12% of waste heat is recycled, giving a total efficiency of 96%. The company’s first product, a portable microwave heater, is now in production for military customers.

 

[fronty]

The electricity load will be about the same as an electric oven, the makers say.

Hmmm interesting, I think most ovens are a couple kw, so it will take ages to heat the water in the mornings, unless there's some kind of boost function to pump more energy in at the start of the heating cycle, but even then the absolute maximum you could get from a 30A feed is 7.2kw... that's not much more than a modulating gas boiler.

To be honest it sounds like a hybrid boiler would be the way to go, start the cycle on gas (maybe running on hydrogen?) then when the boiler modulates down, switch onto electric to maintain the flow temps.

 

[Timmy D]

It still requires a certain amount of heat energy to get water to a desired temp.

It doesn’t matter how that energy is used, you can’t make more energy from nothing.

A typical oven amount of energy will not provide enough heat energy for a typical house.

 

[fronty]

Indeed, there seem to be a couple issues, 1) I'm not sure how a microwave boiler running off a 30A mains feed could heat enough water quickly enough (I mean it would get there eventually but it would take forever) and 2) even if you could get a microwave boiler to produce 26kw of output (eg same as a typical domestic boiler), that would require over 100A of power and the costs would be horrendous.

These Heatwayv people must have solved all these problems somehow so I'm guessing they've got some pretty funky technology else I can't see this being viable.

 

[Timmy D]

Indeed, there seem to be a couple issues, 1) I'm not sure how a microwave boiler running off a 30A mains feed could heat enough water quickly enough (I mean it would get there eventually but it would take forever) and 2) even if you could get a microwave boiler to produce 26kw of output (eg same as a typical domestic boiler), that would require over 100A of power and the costs would be horrendous.

These Heatwayv people must have solved all these problems somehow so I'm guessing they've got some pretty funky technology else I can't see this being viable.

I can’t see it being any different to an electric boiler.

 

[Chuck]

Heatwayv (A new way to transform how we heat our homes | Heat Wayv - https://www.heatwayv.com/),

Anybody who claims they have a method of heating water with a domestic electricity supply that is more efficient than using traditional (resistive element) immersion heaters is mistaken.

There is a section in the link's FAQs, 'How is the Heat Wayv different to a resistive/immersion coil?'. The explanation given, in my opinion, is pseudoscientific nonsense. It's so wrong/confused I suspect that it may actually be a parody.

The current enthusiasm for energy efficiency is going to spawn a large number of gadgets that claim to break the laws of thermodynamics. As always, if it seems too good to be true it probably is.

 

[Ric2013]

Anybody who claims they have a method of heating water with a domestic electricity supply that is more efficient than using traditional (resistive element) immersion heaters is mistaken.

Unless it's a well-specced heat pump, of course. Which is a bit of cheat really because actually you're 'stealing' the heat from somewhere else (not a bad thing, but just to be clear what we're talking about).

 

[Chuck]

Unless it's a well-specced heat pump, of course. Which is a bit of cheat really because actually you're 'stealing' the heat from somewhere else (not a bad thing, but just to be clear what we're talking about).

A good point. The device in question is not, however, a heat pump.

 

[Timmy D]

Just had a look at the site, it is basically an electric boiler that uses microwaves to transfer the energy. Electric boilers typically state 99% efficiency.

This water microwave can’t have 100% A’s there will always be some losses, so not really an amazing new invention.

They also state you’ll need to be trained to install them. They will need a large electric supply, so do you train/certify plumbers as electricians or the other way round? Or does the homeowner need to pay both a plumber and electrician!

 

[fronty]

Well it looks like we'll be using Hydrogen boilers soon anyway, Hindenburg anyone? Millions of homes could be hydrogen-powered by 2030 - will bills rise? - https://mol.im/a/9905101