What Should I Do With Excess Power Off-Grid?

[AgroVenturesPeru]

Most days I top out my 14kwh battery bank before 11am. I thought about doing crypto mining, but my internet is abysmal. Any other ideas?

 

[houseofancients]

waterheater seems like one ?

 

[OffGridInTheCity]

I've gotten comments ranging from buy an electric car (if you don't have one yet) to run a freeze dryer to prep some food storage. I did a rain-harvest system and the pump + UV uses a little power. Maybe a treadmill - and get fit using power? I've already done hot water, whole house heat-pump, dryer, etc etc.

In my case, I'm slowly expanding to have enough power in winter - so I'll have excess in summer and I'm just coming to grips that it's OK 'to not use excess PV power' if my goal is to power my home all year round and yet stay off-grid.

 

[Ralphloren]

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[Ralphloren]

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[drspastic]

I've gotten comments ranging from buy an electric car (if you don't have one yet) to run a freeze dryer to prep some food storage. I did a rain-harvest system and the pump + UV uses a little power. Maybe a treadmill - and get fit using power? I've already done hot water, whole house heat-pump, dryer, etc etc.

In my case, I'm slowly expanding to have enough power in winter - so I'll have excess in summer and I'm just coming to grips that it's OK 'to not use excess PV power' if my goal is to power my home all year round and yet stay off-grid.

sell it to next door?

 

[OffGridInTheCity]

sell it to next door?

It crossed my mind but there's liability/trust issues and if someone got wind of a 'power cable' running from my house to the neighbors.... or a neighbor's house caught fire or xxx. Yikes.

 

[wattmatters]

Using, moving and/or storing heat is the usual option, along with pumping water.

Space heating/cooling, water heating/storage.

Cooking / food prep / food driers (e.g. for dried fruits).

More battery / EV / battery powered garden/yard equipment recharging.

Water pumping / (light) irrigation.

My off-grid PV system is way under utilised, just keeps backup batteries at float and runs the pool pump plus a few sundry electronics.

sell it to next door?

Don't know what the regulatory environment is like where you are but that would be illegal in Australia.

 

[drspastic]

so much red tape and distrust these days. if you have a well i would say build a water tower and use it for water and energy storage.
pumped hydro is still better value than battery. but theres probably a law against that too
my neighbour is burying an insulated ibc (hot rated) under his drive. he intends storing heat in water then pumping into radiators.
personally i think he will need several tons of array to get decent power on a cloudy short winter day.
i have a device called sokovarka that is a 3 tier steamer that extracts fruit juice concentrate. it eats 3kw easily and the juice syrup is ideal for cocktails or fermenting to fruit wine. i also found a small oven that has the old clockwork timer. that is good for a few loaves of bread etc.
all the above run on dc direct from my string. so do my garden tools. chainsaw, small rotavator, brushcutter, etc. you may find brushes and switches burn quicker though so put a capacitor.

almost forgot to mention the still!

 

[OffGridInTheCity]

so much red tape and distrust these days. if you have a well i would say build a water tower and use it for water and energy storage.
pumped hydro is still better value than battery. but theres probably a law against that too

I have 3 x 2500gal water tanks as part of my rain harvest. I did some math on the idea of raising them maybe 10ft in the air with excess PV and then generating power as they lowered back down. Unfortunately, this kind of 'mechanical' power generation - e.g. lower 8tons by 10ft is *very small* amounts of power - on the order of <100w.

Similarly there's a youtube guy @Quint Builds that did a rain gutter generator - and achieved ~2w of power in heavy downflow after much work.

To me - its startling how much mechanical energy it takes to generate power. Whereas solar panels just sit there and as long as the sun is available, they produce like crazy

 

[JWLV]

How about growing your own food? Hydroponics pump, grow lights, heater, etc. I've done this on a very small scale, growing wheat grass, green onions, cilantro, alfalfa sprouts.

 

[crossy]

Electric car is not a bad idea either!

Make it a plug-in hybrid and your on a good thing

 

[corporate.joe]

Most days I top out my 14kwh battery bank before 11am. I thought about doing crypto mining, but my internet is abysmal. Any other ideas?

Crypto mining doesn't use a whole lot of bandwidth. Latency could be an issue I suppose. I imagine anything below 80ms would be fine.

My 57.5 mega hash card is only using 500MB a month.

Joe-

 

[The Dish Doc]

I have 3 x 2500gal water tanks as part of my rain harvest. I did some math on the idea of raising them maybe 10ft in the air with excess PV and then generating power as they lowered back down. Unfortunately, this kind of 'mechanical' power generation - e.g. lower 8tons by 10ft is *very small* amounts of power - on the order of <100w.

Similarly there's a youtube guy @Quint Builds that did a rain gutter generator - and achieved ~2w of power in heavy downflow after much work.

To me - its startling how much mechanical energy it takes to generate power. Whereas solar panels just sit there and as long as the sun is available, they produce like crazy

Even panels take mechanical energy to manufacture.

 

[45North]

Sell ice cubes? frozen food?
What's your budget?
How much more are you willing to invest so you don't "waste" the excess power?
And why did you make such an overbuilt system in the first place?

 

[drspastic]

How about growing your own food? Hydroponics pump, grow lights, heater, etc. I've done this on a very small scale, growing wheat grass, green onions, cilantro, alfalfa sprouts.

can confirm this is good idea. i built a system that has run a few years now. i took box section aluminium and put 450w of 220v driverless leds on it. inside is one long tube and one short tube sealed in each end with sikoflex.
water is moved with central heating pump to radiators in my living room. leds run direct from string. i used to overvolt them and sometimes a chip blew a diode but just reverse connections and use the other side of the built in bridge.
i prefer flood and drain with a heating coil from the cooling circuit in the nutrient feed tank and bubble pump.
i wont mention what i grow but it saves me more money than a standard electric bill and all the power ultimately ends up as a warm house because in essence every machine is a heater, and 100% efficient. some machines do other useful stuff in addition.
its useful to think of energy this way so you make best use of it all.

 

[Ralphloren]

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[timselectric]

Hopefully free electricity was part of the deal.

 

[Ralphloren]

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[Jordi]

Most days I top out my 14kwh battery bank before 11am. I thought about doing crypto mining, but my internet is abysmal. Any other ideas?

You could try to produce a liquid fuel out of that excess electricity. Easiest would be hydrogen, but unfortunately that is a gas and difficult to store.