Tim Howard
Well-known member
Please be gentle - I don't normally venture into this area!
A good and long standing customer has a conference centre with a swimming pool.
The swimming pool has two 1700w filtration pumps that run 24/365.
(the same pump system also handles chemical dosing and water heating via a heat exchanger from bio-mass)
The question has been posed to me whether a nearby roof use could accommodate some solar panels with the specific goal of reducing the operating costs of these pumps.
I will share my attempt at mathematical reasoning and thinking, please feel free to fall about laughing, and maybe once vertical again give some advice....
2 x 1700w pumps = 3400w
In a 24 hour period, consumption is 81.6 kwh
I believe in the UK you can reckon on between 2 and 4 hours direct sunlight on PV panels. Advice seems to be work with a figure of 2.5 hours average for estimation purposes over a year?
I think we could fit (size wise) a 20kw system on a suitable nearby roof and this might be expected to generate 20 x 2.5 = 50kwh.
However during the direct sunlight hours, consumption from the pumps would be between 8.5kwh and 13.6kw depending on time of year.
Sticking the surplus in battery storage seems sensible, but this is where my ability to do calculations fail.
What I'm struggling to work out is how far the 'spare' 36kwh in the sunlight hours would go towards charging batteries, and therefore for how many hours a day the batteries could be the source of power for the pumps before it reverts to grid. I'm also wondering if battery systems are designed to be cycled to this degree.
The ultimate aim is working out if a battery system is feasible at all and eventually what the payback time would be.
Thanks a lot for any hints!
A good and long standing customer has a conference centre with a swimming pool.
The swimming pool has two 1700w filtration pumps that run 24/365.
(the same pump system also handles chemical dosing and water heating via a heat exchanger from bio-mass)
The question has been posed to me whether a nearby roof use could accommodate some solar panels with the specific goal of reducing the operating costs of these pumps.
I will share my attempt at mathematical reasoning and thinking, please feel free to fall about laughing, and maybe once vertical again give some advice....
2 x 1700w pumps = 3400w
In a 24 hour period, consumption is 81.6 kwh
I believe in the UK you can reckon on between 2 and 4 hours direct sunlight on PV panels. Advice seems to be work with a figure of 2.5 hours average for estimation purposes over a year?
I think we could fit (size wise) a 20kw system on a suitable nearby roof and this might be expected to generate 20 x 2.5 = 50kwh.
However during the direct sunlight hours, consumption from the pumps would be between 8.5kwh and 13.6kw depending on time of year.
Sticking the surplus in battery storage seems sensible, but this is where my ability to do calculations fail.
What I'm struggling to work out is how far the 'spare' 36kwh in the sunlight hours would go towards charging batteries, and therefore for how many hours a day the batteries could be the source of power for the pumps before it reverts to grid. I'm also wondering if battery systems are designed to be cycled to this degree.
The ultimate aim is working out if a battery system is feasible at all and eventually what the payback time would be.
Thanks a lot for any hints!
