Newbie solar power questions

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nightowl
Posts: 100
Joined: Sun Feb 03, 2019 1:25 am

Newbie solar power questions

Post by nightowl »

Newbie to solar power, and general technomuppet, so you have been warned. :D
I've been looking at the portable units you see advertised on Amazon but how do you calculate what size of panel to buy and what the energy it stores might power. I've got no idea what might be useful for charging a phone or powering a small radio and what might be useful for powering a larger appliance like a TV.
Winterprep
Posts: 161
Joined: Thu Oct 15, 2020 7:55 am

Re: Newbie solar power questions

Post by Winterprep »

First off solar panels don’t store power but produce it.

You need to decide what you want to power and then find out what wattage of power it uses then you will have some idea of the size of panel needed.

Most people use their solar panels to charge up battery banks be it leisure (caravan) battery or something like the all in one systems like EcoFlow,Bluetti etc or it’s on grid tied systems.

To power something direct from a solar panels don’t you would need almost perfect sunlight and angle of panel.

Search the forum as there are plenty of posts on solar or go onto YT and search some videos there to help.

There’s a good series by a former member here search for English Country Life on YT they are a fantastic couple with lots of smallsteadin and self sufficiency experience.

WP.
jennyjj01
Posts: 4192
Joined: Sun Jun 04, 2017 11:09 pm

Re: Newbie solar power questions

Post by jennyjj01 »

nightowl wrote: Sat Apr 11, 2026 2:24 pmI've got no idea what might be useful for charging a phone or powering a small radio and what might be useful for powering a larger appliance like a TV.
Solar generating exists on quite a scale with different costs{tens of pound to thousands}, different capabilities and differing levels of techy knowledge needed. Some offerings are integrated solutions like a Jackery Power Station, but I'll start from first principles:-

A solar panel produces energy from the sun roughly proportional to its surface area.
One of, say, 30cm x 40cm might generate 25 Watts(Enough for slowly charging a laptop or a few phones) while one of 1m x 2m might generate up to 450W (Enough to run a few small appliances)
The energy is presented as a DC voltage from about 18V to 60V for a big one, but it's only working in sunlight, so we would normally want to store energy in a reservoir battery. Some small solutions just include a USB charging lead and leave it with you Not much use in just a solar panel unless it has a little bit of circuitry in it to convert the voltage to charge something like a USB phone charge connector.
So then, typically comes a Solar Charge Controller, which is used to attach the panels to some sort of rechargeable reservoir battery, such as a car battery. A 150W panel, a Charge Controller and a car battery ( or Leisure Battery) might be used on a caravan, allotment shed or barge, etc as a complete 12V supply for lamps and small tool chargers.
But, if you aspire to get 240V mains from your stored energy, You need to add an Inverter to your battery. That would only give you low power mains to drive, say a small TV, but not enough for heating or cooking devices.
A 'Power Station' integrates those items and are popular with preppers and occasional off grid campers and caravan users.

There's a new kid on the block, coming soon to the UK called a 'balcony system' These pump generated power into the home to offset your electricity bill, they can work with or without special storage batteries ( at a cost)
And then there's the multi-panel home system, professionally installed for many thousands of pounds. Such systems may or may not include storage batteries or might sell surplus energy to the mains electricity supplier.

Beware of some cheap Chinese kit on ebay that grossly overstates the power rating of the panels. If you see panels with ringlet holes for mounting, they are likely rubbish.

Also beware scam adverts for £500 'power stations' at about £70 on Facebook marketplace
I'll send you a private message with some more links.
Graceful Degradation! Prepping's objective summed up in two words. Turning Disaster into Mild Inconvenience by the power of fore-thought

Not Feeling Optimistic. Let me be wrong
nightowl
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Joined: Sun Feb 03, 2019 1:25 am

Re: Newbie solar power questions

Post by nightowl »

Thanks for the info
GeraldTheBonzai
Posts: 307
Joined: Fri Oct 08, 2021 7:52 pm

Re: Newbie solar power questions

Post by GeraldTheBonzai »

Before you spend any money, ask yourself two questions, and be realistic:
1. Under what conditions or situation would I use this equipment?
2. If I did have to use it, what would I be looking to power?

The answers can cover a wide spectrum. At one end, it might be:
a. "I want something in the event of a power cut. I want to be able to run the freezer and be able to recharge some devices like my phone. I don't expect the power cut to last more than 6 hours.
or
b."I want to the able to use the equipment all the time. I want to be able to run everything in my house indefinitely. If the grid goes down, I don't even want to know about it - I'm off grid".

If you find you are at the a. end of the spectrum, then there are lots of consumer kits available, from the likes of Ecoflow, Bluetti, Aferiy that are complete solutions (panel, battery/inverter) and that are also portable. Lots of reviews on YouTube of comparisons of the various products - you are in the £1k range. You could build your own, but there is a fair amount of learning.

If you are at the b. end of the spectrum then its a totally different ball game. You are going to need a healthy bank balance, and its not something you are going to build yourself - you are getting professionals in.

Think you will find that most people who dabble in solar (or other energy sources) on here are somewhere in the middle - learnt how to build smallish rigs (or bought them) and then started expanding. One warning - if you get bitten by the solar/energy bug, then it can get a bit addictive...... ;)
jennyjj01
Posts: 4192
Joined: Sun Jun 04, 2017 11:09 pm

Re: Newbie solar power questions

Post by jennyjj01 »

GeraldTheBonzai wrote: Sun Apr 12, 2026 9:22 am Before you spend any money, ask yourself two questions, and be realistic:
1. Under what conditions or situation would I use this equipment?
2. If I did have to use it, what would I be looking to power?...

Think you will find that most people who dabble in solar (or other energy sources) on here are somewhere in the middle - learnt how to build smallish rigs (or bought them) and then started expanding. One warning - if you get bitten by the solar/energy bug, then it can get a bit addictive...... ;)
Also decide whether or not you care about Return on Investment. Do you want the rig to contribute to its own cost or do you just want a little resilience.
It's satisfying being the only house in the street running the TV, Wifi and freezer while your neighbours sit with tea-lights. But at what cost? *
Like Electric Vehicles, initial investment can be huge and never get recouped. It makes me chuckle when I see streets of council houses with their bold solar roofs, realising that when a power cut happens they may be as in the dark as everyone else because they have no batteries **. Many solar installations were bought because of powerful doorstep sales pitches and occasional seductive grants and schemes.

It can become an obsession :)

* In an extended grid down scenario, a modest off grid system could be valuable.

**Most domestic installations are without batteries (grid tied) and do ZERO when the mains goes off.
Graceful Degradation! Prepping's objective summed up in two words. Turning Disaster into Mild Inconvenience by the power of fore-thought

Not Feeling Optimistic. Let me be wrong
GeraldTheBonzai
Posts: 307
Joined: Fri Oct 08, 2021 7:52 pm

Re: Newbie solar power questions

Post by GeraldTheBonzai »

jennyjj01 wrote: Sun Apr 12, 2026 12:05 pm
It makes me chuckle when I see streets of council houses with their bold solar roofs, realising that when a power cut happens they may be as in the dark as everyone else because they have no batteries.
Originally neighbouring had panels installed. Asked them if they were getting a battery. "Why do we need a battery?"

Latest neighbours are very eco. Heat pump, electric car etc. But they do have a (small) battery. "We can run the house off of the sun. Look how green we are".

Asked them if they had a manual transfer switch installed.
" A what?"
jennyjj01
Posts: 4192
Joined: Sun Jun 04, 2017 11:09 pm

Re: Newbie solar power questions

Post by jennyjj01 »

GeraldTheBonzai wrote: Sun Apr 12, 2026 12:54 pm
jennyjj01 wrote: Sun Apr 12, 2026 12:05 pm
It makes me chuckle when I see streets of council houses with their bold solar roofs, realising that when a power cut happens they may be as in the dark as everyone else because they have no batteries.
Originally neighbouring had panels installed. Asked them if they were getting a battery. "Why do we need a battery?"

Latest neighbours are very eco. Heat pump, electric car etc. But they do have a (small) battery. "We can run the house off of the sun. Look how green we are".

Asked them if they had a manual transfer switch installed.
" A what?"
Exactly. There's been a lot of mis-selling and mis-buying.
Imagine having a full roof of panels and not knowing what to do when a grid outage drops you into the dark.
Tell these guys the cost of adding a battery will double the cost of their system and watch them explode.
Graceful Degradation! Prepping's objective summed up in two words. Turning Disaster into Mild Inconvenience by the power of fore-thought

Not Feeling Optimistic. Let me be wrong