Solar panel array to run Koi pond pumps

I wish to use solar power to run my koi pond,have been on your solar calculator,and it tells me that i am using 4920 watts per day(pond pump 150 watts 24 hours aday)(air pump 40 watts 24 hours a day)uv light 15 watts 24 hours aday)
what kind of system would i need.many thanks mark

Unfortunately, you would need a huge system to run that - those are fairly powerful pumps, and if they are on all the time they are using a lot of electricity (as you've probably noticed from your electricity bill!).

On an average British day, the power you need could be produced by a solar panel array of approximately 2000 watts. However, you do of course get more power in the middle of summer than in winter. In summer you could produce that power with about 1000 watts of solar panels. In winter you would need nearer 5000 watts of panels to produce enough power.

1000W of solar panels cost the best part of £5000, so even in the middle of summer it would be a very expensive solution!

Sorry not to be able to be more encouraging.

Cheap solar system for van

hi guys, hope all is well at midsummer, i wonder if you could help? ive just bought a van to live in for the summer and would like to have solar panels to provide electric, i only really want to run some tunes (small sound system) and my laptop. if you could advise on the best (and cheapest)set up i would be very greateful,
many thanks and blessings alex

Hi Alex,

A lot depends on how many hours a day you need to be able to power your laptop and sound system! Laptops can be quite power hungry. However, assuming it's no more than a couple of hours a day, in the summer you can still get away with a fairly small panel. I would go for something like a Kyocera 50W solar panel kit as a minimum; if you can afford a 65W or 85W kit, then they will give you a fair bit more power.

The kits come with solar regulators and all the wiring you need. You will obviously need a battery - if there isn't a domestic battery already in the van the Elecsol batteries are excellent. That should be everything... unless of course you need 240V power as well as 12V, in which case one of the budget Silverline inverters will give you that.

hope that helps, and enjoy the summer!

Amorphous or crystalline - which is a better solar panel for a narrowboat?

Hi, we live on a narrowboat (currently on a Winter mooring in Paddington basin) & have been looking around at alternative energy sources for a while.  I'm interested in either the Unisolar ES62 (probably x2) or Kyocera 130.  It seems the amorphous are probably better suited for UK conditions but I'd be interested to know your opinion on which would be better for our application.

We currently charge via the engine & have 4 x 270Ah batteries & a Sterling regulator but before I get into figuring out what extras I would need, I have to decide on which type is best for us.

Regards, Allan

Hi Allan,

In terms of output there is not a great deal to choose between the two types. You will get slightly better performance from the ES62's in overcast light - perhaps overall about 10% more power per watt rating over the course of the year.

On the other hand, the KC130 is slightly more than double the ES62's rating anyway, so it does make very little difference overall.

There are two other differences to consider when making your decision. Firstly, the ES62s have a plastic coated front, rather than glass, which makes them a little less susceptible to vandalism (though having said that, the KC130s use toughened glass and damage is really very rare). Secondly, the amorphous panels are considerably larger for a given power output compared to crystalline panels. A single ES62 panel is only fractionally smaller than a single KC130 panel - so if space is at a premium on your roof, the KC130 might be better.

Hope that helps. To be honest I think you will find either type works very well, and it will be lovely not having to charge from the engine all the time!

12V lights for catering trailer

I need a 12v replacement for my catering trailer which is usually lit by a 1.5m fluorescent mains light. Will an LED strip give me enough light? Tony.

Hi Tony,

You would need quite a lot of LED lights to give you the same brightness. You might be better (and a lot cheaper) going for 12V fluorescents such as the Trilite 24W. Depending on the size of the trailer you might need several units to give you the same brightness as your original light. If you can find the power of your current light, in watts (it's likely to be on a sticker on it somewhere), you will need about the same wattage in 12V lights to give the same light output.

Andy
Midsummer Energy

Does a regulator stop reverse current at night?

Just another quick question about the solar panel that I've now got bolted to my roof. You've probably been asked this load of times before, but just to clarify - does the panel drain the batteries at night? According to my battery monitor, I am losing some power overnight (a few percent of the charge according to the Smartgauge) - I don't know if this is because the power is actually leaking back through the panel, or because the batteries are just settling down somehow (obviously, I've got no idea about the technicalities behind all this). Is the regulator supposed to act as a diode to prevent this, or should a separate diode be fitted between the regulatorand the batteries?

Thanks, Jon

You don't need a diode when there is a regulator - it stops any power leaking back through the panel.

Batteries do slowly self-discharge of their own accord, so you would expect the charge to drop a small amount overnight. As long as it's only a few percent there is nothing to worry about. If it's a significant amount, either your batteries are getting old and tired and losing charge more quickly - or there is something else draining power on the circuit.

However, it certainly shouldn't be the solar panel draining power if it's going through a regulator - that should prevent any reverse current.

Andy, Midsummer Energy

Running a radiator from a PV panel

Hi - I have a studio in my garden, it is 3.5 m x 7.5 metres. It has electricity, but I want to keep it moderately warm (i.e. above  reezing) because I have computer equipment in it (for day time use I have an oil run radiator). A friend suggested a solar panel to  keep a small radiator ticking over. I don't have a huge budget, is this something I could do at a reasonable cost? Thanks. Sam.

 

Basically, no. It would be an extremely expensive way of providing heat!

Doing a few quick calculations on our solar panel calculator: a 500W electric heater (which isn't much), on for 4 hours a day, needs 3000Wh of electricity. Even in summer you would need 600 watts of solar panels - which would set you back about £3000. In winter, when you presumably need the heat, you would need an array five times as big.

If you've got electricity there already, you're far better off using mains for the heating - if you want to make savings, spend some money on improving the insulation!

Andy
Midsummer Energy

Recharging a 24V electric scooter with solar panels

Hello.
I have an electric scooter that I use to make the 8.5 kilometer journey to work.
The 24v battery is rechargeable and takes 3.5 hours to recharge from the mains with a power supply.
What I would like to know is: can I use a small solar panel to recharge outdoors for longer journeys?

Thank you. Jeremy.

Most solar panels are designed for charging 12V batteries. However, it is easy to charge 24V batteries simply by wiring 2 solar panels in series.

So yes, it would be relatively easy to add some solar panels to give some additional charging of the battery. However, you would have to do your sums and work out just how big a pair of solar panels you would need for the system to be effective! If you had say 100W of solar panels (a fairly big area), that would still only give around 20Ah at 24V on a summers day. They would unfortunately be probably too big to carry around on an electric scooter....

Andy - Midsummer Energy