Solar/Battery/ASHP/EV - what should I get?

Big_Blind

Hi,

I want to save money on my energy consumption. I could virtue signal about carbon footprint and, whilst that may be an additional benefit, it’s all about the £££.  My ideal scenario is that someone else pays, eg the government but, as that looks unlikely, my next best option would be for any monthly repayments for the cost of a system to be largely offset by the savings or from money selling back to the grid so that once the loan is repaid I’m getting lots of free electricity. 

So, I decided that solar panels would be a good idea. I had a guy out to do me a quote and, if anything, what he told me put me off slightly. He told me that the panels would generate using UV so if it was cloudy that’d have no impact on the electricity generated. He even upped the ante by telling me the panels would continue to generate electricity at night due to the sun bouncing off the moon. I really don’t like it when salespeople make outlandish claims as it makes me trust them less. 

The question is whether I should go all-out and replace my combi boiler with an ASHP given that grants pay a large chunk at present? But, gas is still relatively cheap so I’d have to be confident it was worth it given that I can sell excess energy generated back to the grid so wouldn’t need to use it for heating. 

There are other factors like whether I should get battery storage? I have no concerns about outages so it’d be purely to store excess energy or, in an ideal world, charge when the electricity is cheap and then sell back to the grid at more than I paid for it? That’d also mean choosing the best tariff - maybe Oxyopus Flux? But, then it looks like EV batteries may make that battery redundant? Our car is on our drive most of the time. We need to get a new car soon so will likely get an EV but won’t do many miles. It’s unlikely to have V2G comparability but I can see us getting one that does in 3 to 5 years time at which point we’d have a battery up to 20x the size of the one we’d get as part of our solar system. So, would we be better avoiding the outlay and using a tariff like Octopus Go?

My current temptation is to get the solar panels (12x444w) with inverter (3.6kw) and battery (5.3kw). I’m tempted to look into an ASHP, especially if it can cool the house in the summer. I hate the heat as much as I hate the cold. 1C above or below 19C is ideal for me. But, I do think we’ll get an EV in 6 months so it’d be nice to make that work for us. Then, in 3 to 6 years maybe get one that’s compatible with a smart tariff and can be used to buy and sell power?

So, am I missing anything and what would you go for? Happy to answer any questions as best I can, including giving details of exactly what I’ve been quoted. 

Mark_d

You are always going to be paying a premium with new technologies and you cannot be certain what the finances will look like five years down the track.

To save money, like you I had a car on the drive most of the time.  I sold the car and now rely on train/bus/Uber.  I save a significant amount each year when you consider depreciation, maintenance, tax, insurance, MOT, fuel.  EVs do sound attractive but I believe I'm better off by investing my money in an S&S ISA rather than investing it in an EV.

To save money on energy consumption, perhaps consider LED lighting, smart radiator valves, smart sockets...

Reed_Richards

Solar panels: the salesman was a complete liar, don't even think about buying from them.  Solar panels give you most free electricity when you (well most people) need it least.  So you need to sell the spare back to the grid at a decent rate.

An ASHP won't save you much, if anything, in running costs compared to gas.

Battery storage probably isn't worthwhile if you can sell back to the grid at a decent rate, perhaps unless you use a lot of electricity in the evening.  V2H is always just a few years into the future and not actually getting any nearer.

If you show around for the right EV then you may not have to pay any more than you would pay for the petrol equivalent of the same car; look at Vauxhall for example.  Having an EV strengthens the case for a battery because you can charge that overnight at the same cheap rate as you get for your EV.    

Big_Blind

We have a Hive system and smart valves on each radiator which I’ve programmed with the minimum temperatures for each room for different periods of the day and night when they’re likely to be used and only rooms that are very certain have been set to heat on demand - the rest only come up to their minimum if I boost them or if one of the other radiators heats on demand. 

We have the dishwasher and washing machine using apps so, if we were on a smart tariff, could easily have them come on at the most efficient time. All lights are LED’s in the house as well, and I’m a dad so spend much of my life turning off lights and closing windows. 

The car would be a Motability car so all costs (aside from fuel) are covered but we’d miss out on about £75 per week. We don’t care about having a shiny new car every three years, just something that’s safe and functional and cost effective. Bus/bike/walking isn’t an option. We could share a car with relatives that live extremely close by (50 metres) - much of the time they use their second car it’s for my benefit (eg if they pick my son up from school that’d be fine by motability terms) so we could share their car (aside from when my mobility is too bad to get in and out of it) or they could ditch a car and use our ones. Seems pointless them having two cars… but that’s a separate issue.

badmemory

The bit about the moon wasn't an absolute total lie, a major exaggeration as 10 hours worth would barely fuel a lightbulb.  Definitely find another installer.  In July my panels were exporting a lot more than I was using & I use a lot.  Now they are providing around 10-15% of what I use.  So they with my batteries are still saving me money & remember you can fill your batteries at cheap rate during the night.  I would not have a heat pump due to the noise & I like my neighbours.

I would not have solar without batteries & expect payback to take 8-10 years.  So hopefully before I am ninety.

Big_Blind

How noisy are the air pumps? I’m not overly concerned about noise as neither ourselves or neighbours spend much time in the garden. 

My own research suggests that I’d save about £60 per month and that charging the battery and selling back to the grid at a higher rate doesn’t really justify the cost of the battery if you don’t need the battery for things like power outages - plus EV’s have much larger batteries and could be more effective for that in a few years. But, I know next to nothing about the subject. If the savings were closer to the £140 per month loan repayments then I’d jump at the chance. How big is your battery? I don’t think he was trying to say it generates lots per night, but people found easily interpret it as more than a tiny trickle. He also said things that could be interpreted as ‘high pressure’ sales tactics. Nothing blatant but did suggest that it was a really great price on the battery and that it was only until the end of the month… if stock lasted that long. I once had a kitchen salesman trying that, but far more blatant, and I found it extremely off-putting as it erodes trust. They shouldn’t be so desperately transparent when trying to close a sale. It can make a legit company seem shady. 

Reed_Richards

Big_Blind said:

How noisy are the air pumps? I’m not overly concerned about noise as neither ourselves or neighbours spend much time in the garden. 

They about as noisy as the flue from a condensing boiler, although it's a different noise.

Screwdriva

Big_Blind said:

My current temptation is to get the solar panels (12x444w) with inverter (3.6kw) and battery (5.3kw). 

This would be a red flag for me. 12 X 440W panels = 5.25kW, which means the inverter size should be 5kW to better match the size of the system.  Many a cowboy installer will not want to submit the additional paperwork for a G99 application (required for inverters over 3.68kW), so they lazily stick a 3.68kW inverter on. Without knowing additional details of your installation, I suspect this is the case with your quote. 

Without a heat pump or EV, household electricity consumption will struggle to justify the upfront cost of a battery. And so I would not recommend investing in a battery till your EV and heat pump are installed and running, as prices are correcting sharply and the technology is improving rapidly. There is no financial penalty to adding a battery later. 

Installers I use to help others offer 12 Sharp 435W bifacial panels + 12 SolarEdge optimizers + 5kW SolarEdge inverter (20 year warranty) for £5.7K fully installed. G99 and Bird netting included. I would suggest you use this as a quality system baseline for all quotes you evaluate before deciding on an installer for your future PV system. 

michaels

We have all of the above. Saves us a fortune.

Heedtheadvice

I had a guy out to do me a quote and, if anything, what he told me put me off slightly. He told me that the panels would generate using UV so if it was cloudy that’d have no impact on the electricity generated. He even upped the ante by telling me the panels would continue to generate electricity at night due to the sun bouncing off the moon. I really don’t like it when salespeople make outlandish claims as it makes me trust them less. 

Scam, cowboy, pressure sales, downright lies!

Trust less? Trust not at all. Avoid at all costs.

Responses above about generation are the case. e.g. Even if the moon ( when full, in the right orientation, cloudless sky) give a small amount of illumination on to the panels that would be negated by the small power consumption of the electronics in the inverter.

Good you are asking  on here and getting independent info. for starters.

Heat Pumps can be good and work out similar running  costs to gas but they need to be designed and installed as a system I.e. things like power sizing and matched rad/underfloor heating output at the lower temperature. Some have I stalled air to air pumps for the space heating. So needs careful and knowledgeable consideration.

To make financial sense batteries need to be used to time shift charging( at cheap rates) to utilise supply to loads that cannot be time shifted to cheap rates on the best tariffs and/or export back to the grid at times where you get high return for that. Start metering ( or other smart control of charge discharge) is required.

Batts in conjunction with maximised solar panels is another benefit to time shift generation to use periods.

Potential power backup can be an additional benefit if prone to power cuts. Many consider using the grid to impirt export is a bit like a virtual battery. It is not entirely but not the great up front outlay.

Most (if not all) the special tariffs currently require either a heat pump or EV/PHEV to obtain [Trust someone will correct if I am wrong here!].

Currently solar and battery systems ( and their installation) are VAT free though no guarantee that will remain.

MCS certification of installers should give you some confidence and can be necessary but some wild prices have been seen on posts on this forum quickly shot down by members!

You are best to gather as much info as possible  before making a decision.

Solarchaser

I think it's important to separate some of the things you are looking at.
Solar, In my opinion always makes sense as long as you are paying around £1/watt, so a 6kw panel system for £6k will definitely make sense, and 6kw system for £10k will not.

Most of what the salesperson told you was bs, the whole moon making power thing, it could potentially be true,,, but what you need to know about solar inverters is they all have a startup voltage, which is a voltage that the panels need to create, before the inverter will wake up and start producing power, and the moon will never do that.
However startup voltage is important in other ways too.
The panels quoted come to just over 5.3kwp, and the inverter is 3.6kw which is the standard (easy to get approval) system for solar inverters as its under 16a.
One view of this is that its a scam to get you to buy extra panels for no benefit, and given the other lies he/she has told you, that may be true.
However it could also be that the quoter is following the example of many other countries where the panel array is deliberately oversized to maximise output when it's needed most, which is the duller days.
Each panel generates voltage, and say you have 3.6kw of panels generating 60V, but your inverter requires 75v to start up, then you get no output.
However if you have 5.3kw of panels they will be generating perhaps 80v and so your inverter will start up.
The flip side of this is in the cold but sunny days your inverter will clip, that is to say the panels would generate more than your inverter can handle, but that would tend to be alot less days than you might think.

I have set my second system up to be 4.5kw into a 3.6kw inverter for this very reason, I need more solar power in these darker months, than I do in the brighter months. I would have put more into the inverter, but ran out of physical space on the garage roof.

In regards to the various things, some are linked together, and some are completely separate. 
Solar and EV, can be linked together with certain chargers, but mostly they should be viewed separately. 
EV'S and batteries should definitely be viewed separately as you would never use batteries to charge your EV, nor vice versa as the round trip losses would make it a silly endeavour. 

Solar and heat pumps can make sense together especially if you plan on using heat pump for cooling in the summer. 

Solar and batteries should definitely be viewed together as before export tarrifs were a thing, batteries saved money by charging themselves on excess solar and saving you buying electricity. 

People who have solar and no batteries will tell you that batteries are a waste of time, because that's what they have decided.
The same goes for every other version of person on this forum.

Until very recently, if you wanted good off peak rates, you needed an EV to qualify, but EONs newest tarrif which has better rates than intelligent octopus, requires and EV or a battery system, which is a bit of a game changer.

Personally I have solar, batteries and an EV, and would highly recommend them all.
A heat pump would not work for me, firstly because the wife said they are ugly, and so it's a straight no, but also my house runs at 21C, and a heat pump with lower output temperatures would take too long to recover to that 21C by the time the wife has stood at the front door chatting and then came back and said the house is cold.

Finally, this is a forum, you don't know anyone here, and so all posts,  including mine, should be viewed with an element of distrust, always verify by your own research.
You need to decifer if those posts you are reading are from knowledgeable people imparting unbiased information, novices parroting what they have been told, or confident bullshitters trying to sell you on their ideas.