Pandora solar charging


Get a small portable generator :)
That's probably my only option... but the noise would be terrible.
Maybe get an RV/moterhome battery? They are designed for deep cycles (unlike car batteries which are optimized for starting a car), and you can get such batteries in large capacities (over 200 Ah at 12V, so more than 150 Pandora batteries).

http://www.lifelinebatteries.com/rvdeepcyclebatteries.php

http://www.batterystuff.com/batteries/rv/
 
Get a small portable generator :)
That's probably my only option... but the noise would be terrible.
Maybe get an RV/moterhome battery? They are designed for deep cycles (unlike car batteries which are optimized for starting a car), and you can get such batteries in large capacities (over 200 Ah at 12V, so more than 150 Pandora batteries).


http://www.lifelinebatteries.com/rvdeepcyclebatteries.php


http://www.batterystuff.com/batteries/rv/
Now we're talking!


I think a couple of these that get recharged during the day could do the trick:


http://www.batterystuff.com/batteries/upc-telecom/UB8Dagm-45964.html


On my wish list...
 
There are several components to consider when getting into off-grid solar applications. When looking at a 'total solution' the net costs of the components can get a bit shocking.

Solar has the benefit of being 'free' when the sun is shining and you're standing put waiting for the batteries to charge. Most panels can output 80% +/- of their rated capacity on a sunny day at 40* latitude - only expect full output at the equator. However, a cloudy day can reduce the panel's output to 10% capacity and a rainstorm can make the output negligible.

So, any solution that is going to be something you can depend on is going to require a much larger solar array AND one or more big deep cycle batteries. The larger solar array is so that you can, in 8 hours of good light, charge MORE than one 24 hour's day's power needs during one good day of sunshine. Usually you want to get upwards of 48 hours use out of 8 hours of sunshine - and have the battery capacity to hold those 48 hours of charge.

Yes, that gets a bit crazy very quickly.

I was recently asked to look into this for another project - continuous use of refrigeration without mains OR a vehicle to charge from. What would it take to do it 'reliably'? (Meaning 1% or less chance of failure.)

I found a DC electric compressor based fridge/freezer (50qt ARB) that is very efficient and uses around 2A of power per hour with a 60*F differential between the inside and outside temps. So 2 Ah. In a 24 hour cycle it will consume something on the order of 48 Ah - which I'll round up to 50Ah of need per day.

An Optima D31M (marine cycle, 650Ah capacity) would, in theory, yield 11 day's use before it is bone dry - but it's a bad idea to take any battery under 50% of it's charge capacity if you want it to last a long long time. So, rounding again, that gives a 5 day buffer on the solar panels.

Looking at it another way, I need the solar panel to, over a week, replace 350Ah of electricity in the storage cell (big battery).

Starting with a 'big' 60W rated solar array (Powerfilm F15-3600) as a benchmark.

At my latitude (40* North) it should produce under ideal conditions, at noon, aimed directly at the sun around 80% of it's rated capacity or 48W. Half of that when averaged over the 12 hours of light during the day and to take into account no active aiming technology ~24W at 12VDC per hour @ 12 hours or 2Ah * 12 = 24Ah on a GOOD day.

So, the Powerfilm 60W panel, at 51x47" (1.3M x 1.2M) at an average price of around $700 is roughly half of what would be needed in this scenario if all days were sunny. I would need 4 of them to have any form of assurance that the battery charge could be recovered if one or two days in a row were cloudy.

So - what if I did have four of those $700 panels and it was sunny and the battery reached capacity? If that's all that was in that circuit, it would simply boil the battery to death. So, an often overlooked component is a battery maintenance circuit that cuts off the panels after the battery is fully charged. For that you need a charge controller. Those range anywhere from $30 to $300+.

So, in this scenario, to have a working refrigerator in literally the middle of nowhere the costs wind up being astronomical. In rough terms:

Fridge/freezer + insulator bag + shipping ~ $1000

Four 60A solar panels ~ $2800

Big marine duty deep cycle battery ~ $250

Charge controller ~ $50

Wires, connectors, battery boxes, fuse box, etc. ~$150

Project estimate $4250. Odds of failure to provide enough juice to keep the fridge running ~10%. Decreasing that chance of failure requires doubling the system to get to 2.5% and again to get to 1%.

Solar is not exactly 'cheap power', particularly if you need the system to be dependable.
 
Solar is not exactly 'cheap power', particularly if you need the system to be dependable.
Solar sucks if it's the only source of energy you have. Just look at the trouble (biological) plants go through to survive winter -- for many of them, it's easier to just die and start all over in spring with their solar powered activities.

Solar is nice as an extra source of energy if you're already on the grid though, and if your grid can handle getting power back from you. I put 10 panels of 250Wp each on my roof last summer, and since I can use the grid as a 'battery', that is actually about enough to cover my electricity needs.
 
Solar is not exactly 'cheap power', particularly if you need the system to be dependable.
Solar sucks if it's the only source of energy you have. Just look at the trouble (biological) plants go through to survive winter -- for many of them, it's easier to just die and start all over in spring with their solar powered activities.

Solar is nice as an extra source of energy if you're already on the grid though, and if your grid can handle getting power back from you. I put 10 panels of 250Wp each on my roof last summer, and since I can use the grid as a 'battery', that is actually about enough to cover my electricity needs.
Oh, and grid operators hate solar and wind power.  These give them headaches trying to balance the power grid with these unpredictable power sources.  Solar and wind power, to me, are just a mean for those extreme environmentalists to pocket tons of money :)
 
From a grid operators perspective, adjusting load to meet demand is always a concern.

Solar: Time to adjust load capacity to demand (months/years). Reliability of supply: Poor.

Wind: Time to adjust load capacity to demand (months/years). Reliability of supply: Poor.

Hydro/dams: Time to adjust load capacity to demand (tens of minutes). Reliability of supply: Good.

Nuclear: Time to adjust load capacity to demand (months). Reliability of supply: Excellent.

Coal: Time to adjust load capacity to demand (hours). Reliability of supply: Excellent.

Gas: Time to adjust load capacity to demand (minutes). Reliability of supply: Excellent.

Battery: Time to adjust load capacity to demand (seconds). Reliability of supply: Good but very expensive.

So - base loads wind up being handled by Nuclear, Coal or Hydro with Gas handling hourly fluctuations and battery banks used to handle momentary spike loads.

To integrate solar and wind into that mix can be difficult because of their lack of reliability. It can be used to substitute out some of the Gas load IF there is a big battery bank to even out the supply to load.

An idea I had was to use hydro with two reservoirs - one higher than the other (of course) complimented with solar or wind and a battery bank. The reservoir generators would handle the base load and 95% of the peak loads - the other 5% of the peak loads would fall to the battery power - which could be replenished by increasing the hydro output. Pretty normal hydro to that point.

Why augment with solar and wind? Use those strictly to pump water back uphill from the lower reservoir to the upper - using the water and gravity as a big battery. It would loose something in the range of 30% of the power generated from solar/wind to mechanical heat pumping the water back uphill. Not overly practical.

Fun stuff. What were we talking about again?
 
From a grid operators perspective, adjusting load to meet demand is always a concern.


..
You mean adjust generation to meet demand :p

So - base loads wind up being handled by Nuclear, Coal or Hydro with Gas handling hourly fluctuations and battery banks used to handle momentary spike loads.
General public doesn't understand this.  They hate nuclear power plants.  They hate coal plants.  But they have no idea these are the ones keeping the backbone of the transmission grid and these are the ones that keep the electricity prices down.  Sadly, there will be tons of Coal and Nuke plants forced to retire in the coming years.  There will be GigaWatt of power that need to be replaced!  You can't build a power plant overnight and cheap and easy these days you know :)   So don't complain if pices are higher than it is now :)

An idea I had was to use hydro with two reservoirs - one higher than the other (of course) complimented with solar or wind and a battery bank. The reservoir generators would handle the base load and 95% of the peak loads - the other 5% of the peak loads would fall to the battery power - which could be replenished by increasing the hydro output. Pretty normal hydro to that point.
This has been done for ages but not with battery bank.  It's call pump storage.  In the day time when electricity prices are high, they drain the water from the reservoir to generate electricity and sell it to the market.  At night when power is cheap, they buy the cheap electricity back and use that to pump the water up and fill up the reservoir.  Sorry Grench, you idea is not that original :p

Huh?  What are we talking about again?  Oh well, it's about power so it's not that off topic. :)
 
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An idea I had was to use hydro with two reservoirs - one higher than the other (of course) complimented with solar or wind and a battery bank. The reservoir generators would handle the base load and 95% of the peak loads - the other 5% of the peak loads would fall to the battery power - which could be replenished by increasing the hydro output. Pretty normal hydro to that point.
 This has been done for ages but not with battery bank.  It's call pump storage.  In the day time when electricity prices are high, they drain the water from the reservoir to generate electricity and sell it to the market.  At night when power is cheap, they buy the cheap electricity back and use that to pump the water up and fill up the reservoir.  Sorry Grench, you idea is not that original :p
Sure it is - my idea was to use solar and wind in combination with hydro so that solar and wind can help/handle base loads without requiring huge chemical batteries. Buying back off the grid is cheating. :)

Idle thoughts anyway - once it's on the grid who knows where the electrons are off to?

This post created entirely of recycled electrons.
 
So - base loads wind up being handled by Nuclear, Coal or Hydro with Gas handling hourly fluctuations and battery banks used to handle momentary spike loads.
General public doesn't understand this.  They hate nuclear power plants.  They hate coal plants.  But they have no idea these are the ones keeping the backbone of the transmission grid and these are the ones that keep the electricity prices down.  Sadly, there will be tons of Coal and Nuke plants forced to retire in the coming years.  There will be GigaWatt of power that need to be replaced!  You can't build a power plant overnight and cheap and easy these days you know :)   So don't complain if pices are higher than it is now :)
You know, Cole is limited, Oil is limited, Gas is limited.

Only Nuclear energy seems to last for the next century.

Doesn't it make sense to look for energy we can use in the future right now?

Let's prepare for the time Gas and Oil are shore as long as we have those resources.

BTW, not every country is like the US and has these resources on it's own.

Germany has little cole but that's it.

Here it's also a question of more independence.

If Russia decides to break it's contracts for whatever reason and we won't get any Gas/Oil and more we have not that much alternative.
 
The problem with electricity production is not so much the technology that is used, but the fact that in most countries, it is done by private companies who are obliged to maximize profits for their shareholders, which is not the same thing as maximizing consumer satisfaction, ecological considerations, and safety. Disasters like Fukushima could only happen because when maximizing profits, safety procedures and maintenance are typical targets for cost reductions. Also note that there are no private insurance companies that cover nuclear disasters; it's always the government/tax payer who ends up being the "insurer", effectively carrying the risk for free. Just like how banks can be "too big to fail", some electricity companies can essentially gamble with the public health to get more profits while taking very little actual risk themselves.

So I think nuclear power is a valid option to consider, but not if it's run by a private company that will always stick to the cheapest, most profitable way to satisfy any safety regulation -- or if they can get away with it, even ignore the regulation or try to influence the legislator to be less strict (like they do here in Belgium to keep our old nuclear plants open well past the planned lifetime they were designed for).

Coal, and to a lesser extent gas, are to be avoided -- not just because fossil fuel is non-renewable, but also because we better stop increasing the concentration of CO2 in our atmosphere.

I think it would be beneficial to have more collaboration between countries. It is a bit strange to put solar panels on our houses in Belgium and Germany, where the weather is not optimal for that, while in desert countries they are burning fossil fuel. It would make more sense to put large arrays of solar panels in the desert, and use the electricity that cannot be efficiently transported to where it is needed to do things like desalination of water or making hydrogen fuel.
 
To integrate solar and wind into that mix can be difficult because of their lack of reliability. It can be used to substitute out some of the Gas load IF there is a big battery bank to even out the supply to load.
Solar and wind aren't unreliable (weather forecast and such, and I don't mean the forecast that you see on TV) the problem is that they can't deliver enough energy in certain timespans due to the dependency on weather conditions (in both scales: a days profile and a years profile). This could be partially counteracted with better distribution and storage (as you hinted at with "pumping fluid uphill"), but probably will never be usabel to cover the basic load area.
General public doesn't understand this.  They hate nuclear power plants.  They hate coal plants.  But they have no idea these are the ones keeping the backbone of the transmission grid and these are the ones that keep the electricity prices down.  Sadly, there will be tons of Coal and Nuke plants forced to retire in the coming years.  There will be GigaWatt of power that need to be replaced!  You can't build a power plant overnight and cheap and easy these days you know :)   So don't complain if pices are higher than it is now :)
Is that how the public opinion about nuclear power is in the U.S? Always looked to me like that the people in the U.S are generally less technology skeptical. But hasn't the U.S a bigger problem with its rather desolate power grids than with the loss of power generating capabilities.Around here, nuclear power is in decline, even the "evil" corporations don't want to invest in that area. Coal however is on an all time high, due to the cheap price of it. Which is quite sad as a lot of money went into building efficient gas turbines / or gas driven power plants, which are currently put out of service due to coal beeing super cheap.

So I think nuclear power is a valid option to consider, but not if it's run by a private company that will always stick to the cheapest, most profitable way to satisfy any safety regulation -- or if they can get away with it, even ignore the regulation or try to influence the legislator to be less strict (like they do here in Belgium to keep our old nuclear plants open well past the planned lifetime they were designed for).
I don't consider nuclear power to be a viable (future) option. The "fuel" is ecologically and ethically a total disaster (and I'm not talking about radiation), and is also rather limited. And there is the problem with the fission product that is left over. I read about the technologies to recycle that to be reused and to decrease radioactivity of the remains, but there currently is nothing substantanial wether these technologies will be as sufficient as they are looking right now or if they will be cheap enough to be a real alternative. And with the "advances" in nuclear power generation technology we have seen in the past 50 years nuclear energy production is already around, I have my doubts we will see any improvements in the next 20 years.
I would rather see the status quo kept and all the money poured into reasearch on alternative sources (I.T.E.R anyone, I know its still years till we see a "reasearch reactor", and no one is currently even thinking about a commercial one) and more efficient transportation and storage.

I think it would be beneficial to have more collaboration between countries. It is a bit strange to put solar panels on our houses in Belgium and Germany, where the weather is not optimal for that, while in desert countries they are burning fossil fuel. It would make more sense to put large arrays of solar panels in the desert, and use the electricity that cannot be efficiently transported to where it is needed to do things like desalination of water or making hydrogen fuel.
There is (or more or less was) such an undertaking http://en.wikipedia.org/wiki/Desertec
 
Around here, nuclear power is in decline, even the "evil" corporations don't want to invest in that area. Coal however is on an all time high, due to the cheap price of it. Which is quite sad as a lot of money went into building efficient gas turbines / or gas driven power plants, which are currently put out of service due to coal beeing super cheap.
In the UK, we're having to interest the Chinese in building new reactors for us, because no UK company with sufficient clout is willing to get involved. Which of course will cost us more money in the long term, because the owners will need to get a return on their investment which will likely wipe out any improved efficiencies introduced by the new build.

But politicians are between a rock and a hard place at the moment. Stations are shutting down, and they need to replace that capacity sooner rather than later, else electricity bills will shoot up as we have to import fossil fuels to supplant the lost nuclear capacity. So it makes sense to keep bills lower than they would be for the next five, ten years, even if in twenty years the money we own back to the Chinese is a significant part of everyone's leccy bill.


Of course, the immediate situation wouldn't be nearly so desperate if our consumption of electricity wasn't going up and up. And that's something you can put down to a few factors, one of which is that nobody apart from my grandmother hand-washes clothes any more, an another is computers. That's both overpowered GPUs being left on 24/7 to do a bit of web browsing, as well as the rise of battery powered devices which might be comparatively more efficient in themselves, but simply powering a battery and using that battery power adds up to 20% of lost power.


I'm interested in what you see the downsides of nuclear power are. I see that the disposal or processing of spent fuel can be costly and inefficient, which is why I support the development of thorium reactors in the short-to-mid term, but if you have other objections to uranium, presumably some of those would apply to thorium too?


Anyway, I apologies for the off-topicness of this post. If you're off-grid, the efficiencies of batteries is your concern, not that of the grid, so you can do what you like.
 
People die more from drink and drive than from nuclear power plants :)   Look at France, the majority of their electricity is from nuclear.  I haven't heard an issue from France regarding their nuclear power plants. 
 
I suppose there's the shadow of Fukushima over the industry at the moment, and I suppose if a Fukushima event happened to a thorium reactor the result would be pretty similar (albeit less long-lived due to half-lives). God knows what size of tidal wave would be needed to reach most of France though!
 
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