Portable batteries worth considering?

Spies

In my mind the answer is no but just wanted to confirm this.

If I was to buy a portable power station for my fish tank, and have it charge when I only had excess solar, low import or the battery reaches 10% would the savings actually be worthwhile or is it essentially pointless? The fishtank uses a little over 1kwh a day. 

Netexporter

Divide the cost of the battery by 6000 and see how that compared to the cost of a unit of electricity.

Spies

Is that 6000 based on cycles before 80% capacity? 

Netexporter

Doesn't really matter. It'll give a quick ballpark figure to see whether it is worth going into more detail.

Spies

0.0365p for a 256wh battery...

Or 0.18p for a 1024wh battery

I don't really get the 6000, because the smaller the capacity the more favourable it seems, if you could tell me why 6000 I would appreciate it

Netexporter

Most lithium batteries are guaranteed for 6000 cycles. They'll probably last longer but it's a good a number as any to use.

You'd need two of the larger batteries, one in use and one charging. Would you need any other gear, apart from the charger, or will the aquarium kit run directly off the battery?

QrizB

Spies said:

0.0365p for a 256wh battery...
Or 0.18p for a 1024wh battery

I don't think you've done the correct sums!

Here's a Jackery (big brand) portable power station. 240Wh, £260. £260/6000 = 4.3p. So you'll be paying 4.3p per battery cycle (0r 4.3 / 0.24 = 18p per kWh), plus the cost of the power itself.

Here's a bigger Jackery. 1264Wh, £1149. That's 19.15p per cycle (15p per kWh).

Or, for comparison, here is a Solis hybrid inverter plus 2x2.4kWh Pylontech batteries. 4.8kWh, £2765. £2765/6000 = 46p per cycle, 9.6p per kWh.

badmemory

Surely some of this depends on the value of the fish in the aquarium.  Last time I had one we had discus at £40 a piece (over 30 years ago) until they became a breeding pair after that the sky is the limit.  Well until a flash of lightening & they ate the lot.  If we had fish now that needed keeping up to temp with regular powercuts, well you do what you need to do if they have value to you.

Spies

QrizB said:

Spies said:

0.0365p for a 256wh battery...
Or 0.18p for a 1024wh battery

I don't think you've done the correct sums!

Here's a Jackery (big brand) portable power station. 240Wh, £260. £260/6000 = 4.3p. So you'll be paying 4.3p per battery cycle (0r 4.3 / 0.24 = 18p per kWh), plus the cost of the power itself.

Here's a bigger Jackery. 1264Wh, £1149. That's 19.15p per cycle (15p per kWh).

Or, for comparison, here is a Solis hybrid inverter plus 2x2.4kWh Pylontech batteries. 4.8kWh, £2765. £2765/6000 = 46p per cycle, 9.6p per kWh.

So from the point of view of saving money by running things from a power station is basically a waste of time if you're being paid for export

QrizB

Spies said:

QrizB said:

Spies said:

0.0365p for a 256wh battery...
Or 0.18p for a 1024wh battery

I don't think you've done the correct sums!

Here's a Jackery (big brand) portable power station. 240Wh, £260. £260/6000 = 4.3p. So you'll be paying 4.3p per battery cycle (0r 4.3 / 0.24 = 18p per kWh), plus the cost of the power itself.

Here's a bigger Jackery. 1264Wh, £1149. That's 19.15p per cycle (15p per kWh).

Or, for comparison, here is a Solis hybrid inverter plus 2x2.4kWh Pylontech batteries. 4.8kWh, £2765. £2765/6000 = 46p per cycle, 9.6p per kWh.

So from the point of view of saving money by running things from a power station is basically a waste of time if you're being paid for export

It depends on the difference between import cost and export payment, but yes, if you can buy power from the grid for eg. 10p/kWh more than you get for export, batteries are unlikely to save money.

Bear in mind that, prior to about 12 months ago, Octopus Outgoing Fixed was one of the better export tariffs at 5p/kWh. It's only recently that 15p/kWh export payments have become available.

paul991

but if you charge your battery cheaply to self consume your saving your self 21 pence kw ie  between economy 7 and peak time but the main use of portable power packs is to be able to keep power on if essential