Larger Garage

MouldyOldDough

We have a single garage - a concrete Comptons 21 feet by 7 feet approx. Would it be possible to extend it, width-wise to make it a double size retaining both side walls with a new double door – no idea what the roof would need (its an Apex) – it is fine, length-wise. We have the space and just need the concrete base extending. This would make it much easier to park in it – I have never parked IN it in the 23 years since we had it built – too narrow.

Emmia

https://forums.moneysavingexpert.com/discussion/6664761/larger-garage

Presumably you're not interested in a demolition and rebuild to the size you want?

Section62

https://forums.moneysavingexpert.com/discussion/6664761/larger-garage

I'd say the feasibilty depends on whether you can source some additional panels of the right type (probably unlikely unless very lucky).

I've converted a single garage into a larger shed, but that was only possible because we had a spare panel and inserted three windows meaning there were 4 'spares' which allowed a two-panel increase in width. (the front was made up with doors plus a timber panel).

When that shed was life-expired the panels were again reused, this time with an 18" wide cast in-situ concrete panel to fill a gap. I wouldn't recommend this technique for anything wider as doing the shuttering wasn't easy.

In theory it would be possible to use the precast panels to make two 'L'-shaped walls and do a brick/block section to fill the gap between them. However this would need to be done very carefully as it won't be easy to tie the the brick/blockwork to the panels, and the loads on the 'L'-shaped sections may cause them to pivot along the long side which could impose an uplift force on the brick/blockwork. It would work better if you were happy with just a timber infill panel.

TBH as you'll need an entirely new roof and door, there may be no cost saving reusing your panels vs getting a new brick/blockwork garage constructed. The saving on materials could easily be offset by the labour cost involved in crafting solutions to the problems you'll encounter in the reuse.

MouldyOldDough

So it looks as if its got to be a demolish and fresh start ?

Comptons are no longer going so what's the best option for supplier/installer ?

I don't want a hybrid - wood/concrete - I want 100 % Concrete

onomatopoeia99

https://forums.moneysavingexpert.com/discussion/comment/81969259#Comment_81969259

Lidget Compton still have a website. https://www.lidget.co.uk/

I had one of their garages installed approx 15 years ago and it's stilll absolutely fine. Looking at the construction and watching as the bloke built it from the panels, taking it apart and rebuilding seems doable but as well as laying the base you'd still need extra panels, a new door and new roof so not really worth the effort.

Section62

https://forums.moneysavingexpert.com/discussion/comment/81970255#Comment_81970255

Their website does have a section about refurbishment, which implies the possibility of them having at least some replacement panels available. The refurbishment service is only available in South & West Yorkshire, but there's probably no harm in contacting them if in a different area to find out what they might be able to do.

MouldyOldDough

OK I have been in touch with Liget Comptons and are interested in a double garage with apex roof - Spine N-S with very little shade

Fitted with as many solar panels as we can fit - looks like 12 or 14

What would this allow us to do ?

Not only power the house (average elec consumption 3 kWh /day at present) heating is gas at present ?

Also charge a decent size battery for night time/dull time use - and charge an EV - Would this be possible ?

And if it is - we would like to be able to sell excess power back to the supplier - but only when the car is 100% charged etc - how flexible is a solar system ?

secla

5-6 kwh system

probably enough in the summer depending on orientation but not in the winter

also depends on what mileage you do in the car as thats a big drain

MouldyOldDough

https://forums.moneysavingexpert.com/discussion/comment/81984341#Comment_81984341

Probably around 6000 miles per year as a maximum - I was hoping to cover heating the house as well ??

We have decided that if we're going to do it - do it properly

WIAWSNB

https://forums.moneysavingexpert.com/discussion/comment/81983867#Comment_81983867

Hi MOD.

Interesting!

I have had a PV system fitted for around 15 years now, so hopefully can provide some insight, tho' not remotely all.

Mine is 16-panel but old-school, so is around a 3kW system. In ideal conditions - bright sun plus cool - it rises to around 3.3kW output, but it's usually below 3kW, and much much less on dull days. Right now, it's drizzly and bright-overcast, and outputting 500W, which is just abut covering 'background' and most of the W/M's current draw which is only rotating the drum.

You want/have an EV, and do around 6k miles pa. Based on my Phev's 14kWh battery which gives ~40-mile range in ideal (mild) conditions, I 'calculate' that your 6k miles can be maintained by ~6kWh of charge per day. So, on brightish days, you should be able to provide its 'daily top-up requirement' in less than 2 hours. In practice, of course, you are likely to have good sunny days of no other power drain, so the car could receive a good 8-plus hours of solid charge, so it'll run for a week or so, but on other days, it'll receive now't.

So, a careful calc should be made on how charging the car this way compares with a cheap overnight (and possibly other off-peak times) charge at, say, ~7p kWh. And, if that type of tariff is of interest, then why not also use it to charge up batteries at that same low rate? That way, Summer or Winter, you should be able to store a whole day's leccy use at the lowest supply cost.

Whether that would also be enough to supply your heating in winter, I don't know, unless you have a battery system that can charge at a faster rate. It should be 'easy' to calculate - add all the power required over 24 hours in the worst case conditions - essentially freezing Winter; heating plus cooking plus car - and work out what size battery would be needed for this. I suspect 'big' - 20kWh or more? Then work out what the cost of filling this will be at the lowest rate, and then how this compares with anything else!

Of course, there is likely to be a cost tipping point - you could pay out a large amount for a large battery so it covers you in the depths of Winter, but it'll then be largely redundant for the rest of the year (except for exporting). So, it may be more cost-effective to go 3/4-size, and be happy to use a bit of gas or direct-draw leccy to top up your heating on the coldest evenings…

Someone must have done these calculations?!

As for flexibility, yes, everything is possible. In Summer your batteries would be hummin', so that would be the ideal time to export your excess power to the grid and get paid for it. Of course, in Summer the demand is also going to be less, but there must still be times of high demand - mornings and teatime? - where you'd be paid a fair amount for this. (And who knows what daytime aircon and AI will do to this.)

I think what I have talked myself in to is, for the installation cost and hassle, try and compare a PV/smaller battery system with a fully-larger-battery installation that uses cheap leccy.

I think, but do not know, that battery-only may make more financial sense. Could anyone confirm?

bob_a_builder

Re - Battery Only …..
There is a YT video discussing ROI here (mainly in relation to 'Plug In' systems)
https://youtu.be/j4qF86jRj7A?t=872

The reason for referencing that video is that he has produced a tool to calculate ROI
https://www.jonathantracey.com/ecoflowstream-battery-roi-tool
Not sure if it can be used/helpful in non Ecoflow cases