Hello from Long Beach California

[bln_spt]

Hello everyone,

This is my 1st time joining the solar power community forum. I guess its about time to get serious with this technology. I'm a DIY handyman as far as weekend goes etc. I'm also a fan on building computers since they came out with intel 8088. I'm also into gaming community etc and recently digital coins. Just a brief bio, I'm an electronics technology major but my core job nowadays is broadcast technology design. So this is what I want to get out of this forum community.

1. I've been wanting to build a solar heating pool for the last 10 years..(the tube type) I know its a different topic but lately I figure that I also want to cut down the cost of the energy hog pool pump that runs 2-4 hours a day. So I'm thinking on just starting a solar panel to power my pump for starters. From my online research, I believed pool pumps run around 350w-400w..I have a 23,000 gal pool..so its farely small.

2. So with the pool pump up and running only several hours a day..I also want to use that free power for a couple of computers that run 24/7.., let just say the average wattage consumption is around 1200W and another 650w.. Yes I'm using a Killawatt meter to verify this..

Sorry for my lengthy introduction.. I will be pasting my introduction in my profile too..

[Volusiano]

Wow, you call your 23K gallons pool fairly small? Here in AZ, a small pool is maybe 12K gallons. 23K gallons would be considered a big pool.

You didn't say how big your pool pump is. Is it 1HP, 2HP, 3HP? Is it single speed or variable speed?

Running your pump for only 2-4 hours a day seems kinda short. But then you have different weather in CA. In AZ, you almost need to run the pump for about 8 hours in the summer time and 4 hours in the winter time to keep the water clear enough.

My pool is 16.8K gallons, I used to have a 3HP Pentair pump that ran at 3450 RPM and consumed about 3000W when run. It would take a little over 3 hours to have 1 turn-over of the water in my pool.

I recently switched to a variable speed 3HP Pentair pump and now run my pump at only 1400 RPM which only consumed 260W to run (less than 1/10 the power demand of my old single speed pump). I now would need to run it for about 8 hours to have 1 turnover of water in my pool. But even so, now I'm consuming only about 2 KWH of energy to get 1 turn-over, as compared to 9 KWH to get 1 turn-over before with the single speed pump running at 3450 RPM). That's 22% of the energy demand compared to before. And it's much more quiet, keeps the water in circulation for much longer as well.

Anyway, to make the long story short, if you want to reduce the energy demand from the pool pump, switch to a variable speed pump if you haven't done so already. The energy demand of a pool pump grows almost exponentially with the RPM. You mentioned you think that pool pumps run around 350-400W. That's probably variable speed pump running at around 1800 RPM. To give you an idea of how steep the curve is, below is some data point for my variable speed pump.

RPM Watts
3450 2550
1500 295
1400 260
750 120

If you're going to add solar heating (the tube type) on your roof, however, you may need to run your pump at a higher RPM to have enough pressure to push the water up on the roof, so a variable speed pump may not be as helpful for you, unless the water is already warm enough in the summer that you don't need to run it through the solar tubes in the summer. Then you can run at lower speeds in the summer without the solar tubes, then in the spring or fall to extend your swimming season, you'd run the pump at higher RPM to push the water through the solar tubes. In AZ, the pool water temperature is already too warm to want to heat it anymore than as is. So solar tube heating is only desired early or late in the swimming season only. From that perspective, a variable speed pump still has its usefulness at low RPM all summer long.

I think they do sell pumps that would run off solar panels directly. But I think if you're going to go through the expense of installing solar panels on your roof, why not just size it big enough to make use of grid-tied net metering instead of just specifically for the pool pump only? That way your solar system can become a lot more versatile.

[inetdog]

Hello everyone,

This is my 1st time joining the solar power community forum. I guess its about time to get serious with this technology. I'm a DIY handyman as far as weekend goes etc. I'm also a fan on building computers since they came out with intel 8088. I'm also into gaming community etc and recently digital coins. Just a brief bio, I'm an electronics technology major but my core job nowadays is broadcast technology design. So this is what I want to get out of this forum community.

1. I've been wanting to build a solar heating pool for the last 10 years..(the tube type) I know its a different topic but lately I figure that I also want to cut down the cost of the energy hog pool pump that runs 2-4 hours a day. So I'm thinking on just starting a solar panel to power my pump for starters. From my online research, I believed pool pumps run around 350w-400w..I have a 23,000 gal pool..so its farely small.

2. So with the pool pump up and running only several hours a day..I also want to use that free power for a couple of computers that run 24/7.., let just say the average wattage consumption is around 1200W and another 650w.. Yes I'm using a Killawatt meter to verify this..

Sorry for my lengthy introduction.. I will be pasting my introduction in my profile too..

Welcome to Solar Panel Talk, bin_spt!

Thank you for putting so much detail into your introduction, but I recommend that you also post that information (and Volusiano's reply) as a thread starter in the pool heating area so that more people will notice and join the thread.

[bln_spt]

Thanks @ Volusiano
for the reply. I will move this topic to Solar Pool.