Arctic Sea Ice : Forum

AGW in general => Policy and solutions => Topic started by: DavidR on March 11, 2013, 09:03:15 AM

Title: Off-Grid Is it really a contribution to the solution.
Post by: DavidR on March 11, 2013, 09:03:15 AM
Bob Wallace's thread discussing whether we could have a grid powered by renewables morphed into  a discussion of localised off grid solutions to  generating power.

While going off grid is feasible with enough space and money can it  ever be more than a minor player in the solution.  What are the costs, and what  are the benefits to society and the individual.

At a minimum the proposal seems to  require enough solar to  meet your needs when the sun is shining, enough wind to meet your needs when the sun isn't shining, enough battery backup to  meet your needs when neither of those is sufficent, and enough extra capacity wind and solar to  keep the batteries charged.

With a global grid the entire planet becomes your offsite backup and you can still produce sufficient to  meet  your own needs, If you have the space.

I  have looked at the economics of this several times over the past  few years and have never seen a solution that  comes close to  being economically justified compared to paying my share of the global grid. 
Title: Re: Off-Grid Is it really a contribution to the solution.
Post by: Shared Humanity on March 11, 2013, 05:00:52 PM
I think this is a great question. I believe, however the idea of only two options is limiting. The choice available to every consumer is not limited to on or off grid. Instead, there is a grid dependence contimuum.

I listened to a fascinating lecture given in England online a while ago. I believe the link was on this site. The lecture made two very interesting points. One, we were far past being able to dramatically reduce CO2 contributions if we focus on investments in the generation of electricity. The transition from the world's current electricity generating infrastructure to renewables would be too slow and the global growth in electricity demand would have the effect of consuming the growing contribution of renewables.

The lecturer did offer a path to dramatically and quickly reduce CO2 emissions and this was at the consumer level. If large numbers of consumers individually but simultaneously decided to make personal decisions to reduce electricity consumption, we could halt growth in emissions and then quickly begin to reduce them.
Title: Re: Off-Grid Is it really a contribution to the solution.
Post by: OldLeatherneck on March 11, 2013, 06:54:03 PM

You have brought up an important question.  In my way of thinking about it, those individuals who move 100% Off-Grid are only marginally helping in a global perspective.  However, they are certainly preparing themselves to survive the initial impacts of AGW/CC.  Not having to depend on local infrastructure to provide electricity and water certainly gives them some insulation from the effects of economic/societal decline at the local or regional levels.

I have some acquaintances (retired attorneys), who had a home specially designed by architects who specialize in off-grid designs.  As such, they spent in excess of $500,000 in the process of building their home.  Among the most salient features:

1.  Ample solar panels that charged a series of 24 marine batteries.
2.  Rainwater catchment from the roofs and a 20,000 gallon storage tank.
3.  Self compacting toilets.
4.  Indoor and outdoor facilities for taking showers.
5.  Latest state-of-the-art wood burning stove.
6.  Windows and skylights oriented with respect to the annual solar cycle.
7.  Sandstone blocks purchased from local quarries.
8.  Cedar timbers from local forests.

They are completely 100% off-grid.
Title: Re: Off-Grid Is it really a contribution to the solution.
Post by: Bob Wallace on March 11, 2013, 09:10:40 PM
I'm off the grid, have been for over 20 years, and I don't see it as the solution.  I'm off because it was much cheaper ($10k vs. $300k) than hooking to the grid.

It's an inefficient use of solar panels.  Many days my batteries are full by 11am.  That's hours of potential power others could be using that I can't.  And then there are days when my panels give me only what I need to run during the daylight hours and put nothing into the batteries.  On comes the gas generator.  I'd rather be picking up some wind-generated power from the grid.

We need the grid.  We need to grid to be as "wide" as possible in order to bring the best mix of supplies and to minimize variability.

(Marine batteries are a lousy storage choice.  Tell your friends about the new Trojan T-105 RE.  Designed for off the grid, very thick plates.  Should last 10+ years.)

The lecturer apparently doesn't understand exponential growth curves.  We are at the very beginning of the transition off of fossil fuels.  Installations are increasing around the world at an accelerating rate.  Solar is just now reaching grid parity.  Wind has just now established itself as valuable after years of being poo-pooed by friends of fossil fuel. 

At the same time we are seeing major improvements in efficiency.  Lowering demand, or at least slowing the growth in demand, makes it easier to replace fossil fuels. 

We've cut coal from over 50% to around 35% in the US in only a few years and that's with a half-assed effort.  I think things are now going to get serious.  Watch for very large increases in the amount of rooftop solar that gets installed in the next couple of years.  We now have an established industry and the price is right.

The big problem is storage.  We've got to develop better batteries or start converting existing dams to pump-up.  We've got a few more years before storage will be critical, but we need to be moving forward in anticipation.
Title: Re: Off-Grid Is it really a contribution to the solution.
Post by: Jim Hunt on March 12, 2013, 03:34:00 AM
May I take this opportunity to remind you of one or two other storage options Bob? (
Title: Re: Off-Grid Is it really a contribution to the solution.
Post by: Neven on March 12, 2013, 11:25:48 AM
I've been thinking a lot about this lately and am discussing it with Germans on a PV forum ( A possibility is to be connected to the grid (with a PV array and battery storage) and take electricity from it when needed, but not feeding in surpluses as this is more costly wrt upfront investments (extra meter, extra controller hardware). A friend of mine does it like that, because he was so appalled at how arrogantly the utility company reacted to his plans, which was something along the lines of "sure, you can do that, but you will have to pay us to allow you to feed electricity into the grid".

I don't know, I'd really hate to see my surplus electricity go to waste. I think I'd be even willing to pay for that not to happen. I will post on my plans for PV power today or tomorrow in the topic Lucas Durand opened on green building in the Walking the Walk board.
Title: Re: Off-Grid Is it really a contribution to the solution.
Post by: DavidR on March 13, 2013, 03:42:22 AM
Not  feeding the surplus back into  the grid is an option I  hadn't considered, however it may  make sense in a strange sort of way. 

We currently  get 8c / kwh for power fed into the grid.  The connection cost with new meters  is around $2000 and the price for electricity used  increases by 10% for peak electricity and decreases by  40% for off peak.  Peak runs for about 15 hours a day. As a major proportion of my use is winter heating I suspect the only  way I  would actually  reduce my electricity bill is to  put an extra electric heater on at night and rely on thermal mass to  keep the house warm during winter days. 
Whereas  if I  didn't feed back into the system I  would just benefit from every kw/h I  don't buy from the grid.
Who knows?

There seems to  be a great deal of scope for overselling of the benefits which in the long run supports the deniers claims that it is all just a rort.  Recently  a solar installer suggested I  purchase a system that would, generate  all my winter needs  ignoring the fact that two /thirds of my  winter needs  occur when the sun isn't shining and I  would just have to  pump the extra into the grid and pay full price for the electricity I used at  night.  He put me right off the whole idea.

My feeling is that once we have an efficient grid we can build enough renewable  capacity in to it to  not need the micro renewables we put on our homes.  So  I  would be better off spending my  money reducing my consumption through better home design rather than installing a home energy system. 
Title: Re: Off-Grid Is it really a contribution to the solution.
Post by: gfwellman on March 13, 2013, 08:39:44 AM
It's definitely true that the highest ROI is from efficiency.  If you're building new construction, I'd go with Lucas Durand's outer wall, good passive solar with triple glazed windows, and an interior chunk of thermal mass.  If you're working with an existing finished structure, it's a lot harder, but you can hunt down drafts and apply caulk and weather sealing.  Add insulation where possible.  I've installed double-honeycomb insulating blinds - they weren't cheap, but they're cheaper than new windows.  If you're a book lover, use bookshelves against outer walls as a layer of insulation.  Maybe tapestries will make a comeback  ;)

I figure residential solar might be worth it where I live in 5 years or so.  But if I lived in SoCal, AZ, NM, or similar, I'd be looking at it right now.
Title: Re: Off-Grid Is it really a contribution to the solution.
Post by: Bob Wallace on March 13, 2013, 01:52:10 PM
May I take this opportunity to remind you of one or two other storage options Bob? (

There are multiple possible storage solutions, but none are great.  Yet.  Pump-up is a distinct possibility and we have a lot of existing dams that could be converted for storage.  There's also closed loop pump-up.

Probably the most promising is Ambri's liquid metal battery for large scale storage.  If it progresses past the prototype level where is seems to be working and on to manufacturing scale then it could solve our problems.  Dirt cheap and uses readily available materials.

Another interesting is CAES as being implemented by a company called Lightsail.  They have figured out how to extract and store the heat created during compressing air and then using that heat to re-expand the air during generation. 

V2G might be a good solution, but we're going to need better (larger capacity) batteries.  If people have only 70 to 100 mile range they aren't going to be willing to 'rent out' much of their capacity.  Get range up above 175 miles and V2G could be a big player.

There are also tests underway to store heat in gravel using argon gas as the transfer medium and heat pumps to store/generate the energy.  This could also be a low cost solution.

Hydrogen and ammonia are other options.  But probably too inefficient.
I think we'll have a much better idea of how to store in the next couple of years.  There is a very large amount of research being done.
Title: Re: Off-Grid Is it really a contribution to the solution.
Post by: Bob Wallace on March 13, 2013, 02:00:03 PM
"We currently  get 8c / kwh for power fed into the grid."

That doesn't sound like a bad price to me, depending on what you pay for the electricity you take back.  If you're paying the average 12c/kWh US price then storage/backup power would be costing you 4c/kWh.  I doubt you could store and generate (from fossil fuel) for that price.

Just for example, I need to buy 12 $150 batteries this summer.  They should last me abut 10 years.  Each winter I'll use several gallons of $4/gallon gas.  And a $500 generator will need replacing every 4-6 years.  In addition I have to fill the generator, change the oil, go out after dark to start and stop it on non-sunny days.
Title: Re: Off-Grid Is it really a contribution to the solution.
Post by: DavidR on March 17, 2013, 03:53:40 AM
Unfortunately  Bob, I  don't live in NA and the price for electricity taken back is 34c not 12c.  8c / kwh requires me to input 2500 Kwh per year just to cover the  interest on the cost of converting from my current charging rate to  the new one. 

As a 5Kw system will only provide about 8000 Kwh per year this is a pretty fair chunk of the electricity generated.

Unfortunately because my heaviest electricity use is winter/night it seems PV will never be 'economic' for me. 

Off grid only seems economic if the grid is truly  not available.
I'd much rather have a global grid balancing out the fluctuations of local supply. For this I  see wind as the primary supplier because there is always wind within a couple of thousand Kms.  Solar power is just too far away, particularly in a European, or American winters night.
Title: Re: Off-Grid Is it really a contribution to the solution.
Post by: Bob Wallace on March 19, 2013, 04:13:52 PM
Off grid only seems economic if the grid is truly  not available

I agree.  That's been my point all along.  There are a few exceptions (people with an excellent micro-hydro source, for example), but in general it's more efficient to be connected to the grid and have access to a number of inputs as well as grid-shared storage and deep backup.