Should I invest in solar PV panels, a home energy storage battery... or both?

Just to be aware although things change all the time on tariffs... I am sure things will change. 

I don't think you have an EV? 

I would do some hunting on tariffs that are now available to charge a battery if you don't have an EV.

In theory Octopus Go is only available if you have an EV, but you can use to charge a battery if you have an EV. 

"Our Octopus Go Tariff is designed for customers who either own or long-term lease a battery electric vehicle or a plug-in hybrid vehicle that they'll be charging at home, so you need one to join. If you sign up without one, or you're in the process of getting one, we'll be here to help find you another tariff that's more suitable for your setup in the meantime"

The agile tariff basically doesn't work right now as there are usually no 30 minute price plunges when energy is cheap on the tariff. Octopus are trying to protect agile customers from very high spikes so the average rate is not really  competitive

Perhaps @Jess_OVO or @Tim_OVO could comment on ovo tariffs for battery owners?

Am sure others can comment on the benefits of having solar and batteries based on their experience. 

We have a Phev, so would qualify for Octopus Go.

The failure of Agile to cope with the recent uncertainty and high prices does make these sort of decisions harder. But TOU tariffs are a popular discussion point so you have to hope they will get sorted out.

A fantastic question that I’m keen to understand better myself. 

@Jeffus makes a really good point that the tariff is key. Plans like Octopus Go and OVO Drive are for EV drivers. If I understand correctly, OVO Drive’s Anytime add on is currently a unique proposition for ‘type of use’ EV charging. However we’re trailing a similar tariff for heat pumps. Nothing for energy storage for me to confirm…. yet. However as you have an EV (PHEV), you have options here. 

The next thing is the return on investment (ROI) of solar PV vs storage, when combined with available and future tariffs. Or, is a combination of energy generation and storage the key. For this, we need first hand experience:

@EverythingNeedsAUserName, @hydrosam and @sylm_2000 might be well placed for Solar ROI, and @Bev has been considering storage to combine with their solar generation. 

@Sean T and @mrmhf AND @dnshorto have all posted recently around storage, so are well placed to advise you here if they have any time. 

I’m hoping that @M.isterW is one of thousands of households that are considering these big changes. Investing in your house with green tech now can pay off if done right. Doing nothing or replacing like for like carbon intensive technologies is the alternative. Hopefully some knowledge sharing can help you with your decisions. 

I’ll dump some related threads here in case it helps anyone:

@M.isterW - an excellent question indeed!

I have solar PV for over 8+ years and I joined the bandwagon slightly late to miss out on the lucrative FIT a decade ago (but then the solar PV were more than double the price). Anyway I find that whilst solar PV are an attractive net zero initiative the SE UK (where I am based as well) is not in Spain or Italy to maximise the returns in less than 10 years. Additionally there has been some discussion about risk to roof if you have a rather old property. 

As a viable alternative, the batteries now combined with TOU tariff can easily commercially competitive. I would say the cost of installation is almost the same however the only risk with batteries is the tariff you’re not in control of. A typical domestic solar PV will typically produce 4KW in a year which is not sufficient but consistent year-on-year allowing you to negate some of the increased energy costs. 

In my view, a smaller footprint solution with similar returns might be a better solution.

I have a 3.3 kw system which generates about 3.5Mwh per year. Payback will vary but for me it was about 7 years, but the expected lifespan of the panels is >30 years. Excess generation gets dumped to my hot water tank which takes some of the work off of the heat pump, but not that much in the winter, especially with weather like we have at the moment. 

Now I have a heat pump, a battery is appealing but the capacity needs to be big to help significantly, yesterday the heat pump used about 30kwh, typical seems to be 15-20kwh per day, and the lack of variable tariffs makes a battery less attractive, I’ve struggled to find one. Over the winter when I really need the battery to be charged by the solar PV I have rarely have a day where I have had much excess generated to charge a battery, so most would need to be topped up from the grid.

I can’t find any suitable tariffs that make sense with a battery. The Drive tariffs @Tim_OVO mentions are not available to me because you need to be a dual fuel user and I’ve ditched gas 🙄, but I have an EV… 

@Tim_OVO a segway to this thread, is the heat pump tariff you are trialling going to be trialled with those on the heat pump trial? I’m happy to look at it. 

Yep lets hope the market overall evolves so agile type tariffs can play a part.

For me the current Go rates would be as follows. With enough batteries it should be possible to pick up a good chunk of cheap electricity overnight while you waited for ToU to evolve. 

Unit rate (04:30 - 00:30):

30.83p/ kWh

Unit rate (00:30 - 04:30):

7.50p/ kWh

Standing Charge:

24.01p/ day

Prices include VAT.

SolarEdge PV since October 2015. 4kW nominal but facing East and West in Durham. Average annual production 3.1MWh. Payback (generation, export and actual saving from reduced consumption) will Payback the £6500 cost in about 8.5 years. 

Today was sunless, we had 1.22kWh. In the 4 summer months we average about 15kWh a day. 

I looked at the cost / benefits of batteries about 2018 and couldn't make it pay. Technology may have improved at the same time fuel costs are rising, but unless it works in a power cut, I don't see the point. Even our panels cannot power the house if the external power is lost. I fear that may matter more in future.

@EverythingNeedsAUserName You mention that your panels are facing east and west. Does that mean you have two banks of panels facing in different directions?

You could try the loop app

https://loop.homes/

It attempts to simulate the impact on adding solar and batteries to your home based on your actual energy usage taken from your smart meter and your actual tariff details 

Free to use.

Yes. 6 panels east, 8 panels west. If I'd only been able to put them on one side, it would have been West as we continue to get the evening sun and perhaps that would be most use of electricity.