Replacing gas boiler by an electric boiler

NacNac

Hello everyone,

I have started to do some research and ended up on this website. I found some useful information for various situations but nothing specific of what I have in mind. I therefore decided to post my thoughts hoping that some Energy Guru will tell me if it is a good idea or not.

I am trying to find ways to not use gas anymore and have free electricity.

For the electricity, one can use solar panels, if you have enough surface this could cover all your need even in 20 years when the efficiency of the panels have dropped.

However, the electricity is only produced in the day. which means at night you need to buy electricity. I have found that batteries can be installed. The batteries are loaded in the day (obviously) by the solar panels. Again if the panels provide enough electricity, one will use directly in the day the electricity produce by the panels while at the same time the batteries are loaded. Any extra electricity will be sold to the grid. At night, the electricity one needs will come from the batteries. Here again, one must ensure the batteries are sized correctly to avoid running out or you will need to start buying electricity at night. Batteries goes up to 5kW I believe and more than one can be installed.

I think with such system, I can ensure I will never need to buy electricity again.

Pushing the logic further I thought, if I can have unlimited use of solar electricity (my roof is exposed south and could hold enough panels to produce around 15,000kWh per annum new), why not try to produce heat with the electricity.

The water could be heated directly from the solar panel or batteries with a small modification to the system but yet still a modification.
What about the central heating ?

I then thought that if I could replace the gas boiler with an electric boiler there will be minimum changes to none (except the boiler) to the heating system (central heating and hot water), Even if the electric boiler could end up been less efficient (kind of it has to run longer/work harder than it gas equivalent boiler), it would not matter as I would have enough solar electricity from the panels or the batteries.

In other words, I would need to install the solar panels, the batteries and replace the boiler. That is. this seems quite simple to stop buying any gas and electricity.

Of course when it snows (which is not often where I live in Cheshire), I may run into problems. But I thought this solution is quite simple and use only one type of system rather than a combination of many different ones (I thought of using thermodynamic system to heat the water but they can also be to replace the boiler for the central heating, but they need electricity for their compressor, so I would still need the solar panels to run the compressor but also all the household equipment than use electricity). So the electric boiler seem the less disruptive solution.

What do you guru's and energy expert think of this ?
Has anyone got such installation ?

What would be wrong in going down that route of all electric (while keeping the central heating system (pipes, radiators etc..).,. I am not considering replacing the radiators by electric radiators)

Thanks a lot in anticipation for sharing your thoughts and/or experience.
I hope I have properly explained what I have in mind
Best regards

Pincher

It's the good old Self-Sufficiency versus Specialisation debate.


Is it better for everyone to make their own cheese, some of which really stink and dangerous to your health, or let the ones with knowledge and experience get on with it?


Is a power plant more efficient at generating power, after transmission losses, in terms of resources used, than having your own diesel generator? Is it cheaper to buy gas cylinders, or have it on mains?


Personally, I would prefer to put lots of solar panels where it's sunny, like Spain, so you get more energy per panel, with a small crew to look after thousands of panels. They could be ground based, which is a lot easier to maintain than something on your roof. Good for the Spanish economy, good for the planet.


There is a case for solar thermal, for hot water, but even there the payback could be ten years or more. The next time I change the hot water cylinder, I will put in one with extra solar connections (including sensor pocket), in preparation. Probably combine major roof maintenance, so I have to get the scaffolding anyway, to put the solar panel up.

macman

Work out the capital cost of all the equipment needed to collect and store sufficient power to provide enough heat and power during the winter (when solar energy will be at it's lowest, and heating demand highest). Then calculate the decades it would take to get that investment back in fuel savings. Panels, inverter, batteries...

sheffield_lad

Solar panels great for an investment opportunity, but for trying to heat your home with them??? Good luck with that as Macman has said it will cost you thousands you will never get back. Don't forget good old mains gas is the cheapest fuel you can use. If your not on supply you may consider alternatives than oil but if your already on mains gas forget it and save your money.

NacNac

Hello

thanks for your prompt answers.

I am a long way of actually changing anything at home yet.
It is at the stage Ideation

I am aware that I still have many unknowns and I would refer to my currently energy bills to see how much energy I spend.

Something I am looking at is investing in such equipment and the money I save (therefore not spend) vs if I keep that cash into low rate saving account.

If I understand from your comment, technically it is possible, it is just a question of Return On Investment.

However, as said the project is at a very early stage and it may end up maybe better with more "disruption" ie change in the house eg having thermodynamic panels for warm the house and the water in addition of solar panels.

I am hoping to get more views in the coming days from other people too to start getting a draft.

Thanks again and have a nice weekend.

Best regards

Andy_WSM

I've got a 4kW Solar PV System on a SE Facing roof. Let me show you why it doesn't provide enough for heating in the months you need it.

These are the estimated and actual production figures for 2013:

(exxx) = estimated production, actual reading follows.

January 2013: (e106) a111kWh
February 2013: (e171) a159kWh
March 2013: (e283) a253kWh
April 2013: (e422) a435kWh
May 2013: (e492) a550kWh
June 2013: (e481) a546kWh
July 2013: (e499) a652kWh
August 2013: (e438) a479kWh
September 2013: (e327) a331kWh
October 2013: (e210) a228kWh
November 2013: (e124) a134kWh
December 2013: (e79) a89kWh

As you can see, the months where you would use the most electricity for heating the Sun simply isn't strong enough in the UK to provide it - unless, as ChumpusRex stated you can have a field full of panels!

NacNac

Good morning all.

thank you for your time and comments. Much appreciated.

It looks now that the alternative would be a mix of solar panels and thermodynamic panels to be self efficient.

I am yet to find out how much thermodynamic panels costs.

Regarding the finance, I do not only look at the ROI even if the shorter the better but also compare with the cash seating in some saving accounts with low interest rates. The risk here I see is if the cash is spent on such equipments I could calculate a higher interest rate equivalent but if I come to sale the house in 5 years (who knows what the future is made off). It will be difficult to get the capital back, if you know what I mean.

Have a nice weekend

Martyn1981

NacNac wrote: »

Good morning all.

thank you for your time and comments. Much appreciated.

It looks now that the alternative would be a mix of solar panels and thermodynamic panels to be self efficient.

I am yet to find out how much thermodynamic panels costs.

Hiya NacNac. I like the idea, but unfortunately it just won't work.

Good news - Based on your 15,000kWh pa of PV gen, that suggests approx 15kWp of south facing panels, in a good (southerly) location.

Add in some batteries to get you through the zero generation days that pop up occasionally in the bottom 4 months, and yes you could generate all of your annual leccy and hot water needs, by diverting excess into water heating and batts.

Bad news - No chance of covering your winter heating. Whilst you may generate enough to theoretically cover annual leccy and heating, there is no way that you could efficiently nor economically store the summer excess for winter heating.

Back to the good news, with such a large system, perhaps 5kWp SE 40d pitch, 5kWp south 50d pitch and 5kWp SW 40d pitch (pitches designed to increase winter gen, at the expense of some summer gen), you have plenty of excess to run some inverter type air conditioning units as heat pumps. This may (note may!) cover your heating needs in the shoulder months (Mch, Apr, Sept, Oct) and contribute a little heating to the bottom months (Nov to Feb).

With an exceptionally well insulated house, perhaps passivhaus standard, you'd do even better, but expecting PV to cope 100%, sorry, no chance ...... yet!

Mart.

NacNac

Hi Martin

thanks, just trying (at the moment not too hard though) to get my head around all this.
The 15,000 kWh only comes from an brief discussion from a guy from A Shade Greener who saw the house (his job was just to make aware home owner of potential suitable houses of A Shade Greener. Nothing technical). He said that due to the exposition and size of the roof, they could fit 18 panels to produce roughly 15,000 kWh so it could be that the day I have my roof covered of panels, they can only get 10,000 kWh.

As for the PassivHaus, Infortunately my house is from late 80's- It is 69 for EPC. Not bad but not brilliant either as it is the limit between D and C.

I agree that trying to store the excess of electricity produced in summer for winter use is not something that common and therefore would be very expensive to achieve.

The more inform myself, the more I am going away of the original idea to have all needs (heating and electricity) by solar panels and batteries. If this was so easy, many people would have already done it

I now put my thoughts on thermodynamic panels for the heating (central heating and/or water (water could be covered by the PV panels or dedicated thermal solar panel)).
I have an entire wall facing south west where I think I could have fitted 4 of those panels maybe more and they do not have the constraints from PV or thermal solar panels.

Again, I currently have no idea how much those thermodynamic panels cost. Hopefully I have a better idea in a week or two.

Does anyone have/know someone thermodynamic panels for heating the house and/or the water ?

Best regards

forgotmyname

It will cut your bills but you wont escape from the grid unless you have some backup. Log burner or coal fire etc?

Been a lot of improvements, I think the vacuum tubes was a fairly big step. Seen a video of them fitted a trial setup some time back and they had to be careful because the ends go so hot you couldnt touch them.

Also spotted someone trying to DIY one from some tubes. But tried to use plastic tubing which firstly kept leaking from the join then promptly melted on a fairly sunny day.

I thought about it years ago, Watching guys rig up 12v lighting around the house. Using standard bulbs though it was poor. Using LEDs it can work though.

NacNac

NacNac wrote: »

Hi Martin

---

Again, I currently have no idea how much those thermodynamic panels cost. Hopefully I have a better idea in a week or two.

Does anyone have/know someone thermodynamic panels for heating the house and/or the water ?

Best regards

Hello
I have just found a website which has put some prices
thermodynamicheating dot com

It is a lot more than expected. I wonder how they can justify such cost.

If fitting takes 1 day, this will be a day labour.
The equipment is relatively simple, there is a compressor/pump, an aluminum panels which seems to be made by the same manufacture as all the companies selling it show the same shape of panel. There are some small electrical equipments and the famous liquid which runs at -25°C in the panel. not sure what this product is but it cannot cost 3000 pounds.

so really in term of manufacturing cost, this will hardly be more than 500 to 1000 pounds

So selling it for 7500 (I am talking about the little magic box) is making a huge profit.

Is there anyone with better figures (about manufacturing cost of the equipment for instance) or who can explain/justify such high price.

Best regards