Selfsufficientish.com

Hi folks,

Just how environmentally friendly is solar energy?
Please discuss (and please include the use of batteries in this discussion) :)

regards,

Turtuga Blanku

In short, I don´t know.....but common sense would suggest that a system once made that can replace 20 years of fossil fuel generated fuel, must be the winner.

Batteries are nasty things to dispose of, though due to the rising price of lead they are highly in demand for the recovery of that material. It is a question of how well you look after the system and keeping it monitored. I know people who expect far too much of their systems (thinking they can live "normally" with all the high voltage gadgets they had on-grid) and as so reduce the life of their batteries to about 3 years. Properly maintained and used batteries should last 10 years, at least.

Fact is, if you go off-grid you have to change your lifestyle in some ways.

The question "how environmentally friendly is solar energy" can only be answered, "depends on the person using it".

You have to consider two answers - one for solar hot water, and one for PV. They're just leagues apart in terms of the manufacturing process.

I think a flat panel collector for hot water is far more friendly to the environment to produce as the energy used in manipulating glass is far less. I don't know enough about how the selective coatings are made and applied, but they're important as they're what make flat panels as efficient as tubes.

Regarding PV, I read an article a few months back about a new factory that was being built, but no panels would be leaving it for something like 3 years, as all the production capacity was going to be put on the roof to power the factory into the future. I don't remember the production volumes or energy requirements I'm afraid. Obviously a PV panel factory that powered itself would have a far better lifetime carbon footprint than one powered by conventional means.

Sorry, but I don't yet know enough about batteries to comment.

cheers for the replies so far! :)

It is the batteries I am worried about.

*How much energy does it take to build them? (that new factory making renewable energy system part while running on renewable energy is great!).

*How much pollution is created while producing these batteries?

*How well can they be recycled and at what energy costs?

*How polluting are the substances that cannot be recycled?


This is lifespan information of the Trojan batteries that we use where I live (Caribbean island):

These mass produced deep cycle batteries probably have the lowest cost per amp*hour of any battery of its type and has become the most popular 6V battery for alternative energy powered homes. Use pairs these batteries in series for 12V configuration, sets of four for 24V and so on. Life expectancy is from 3 to 5 years (4 to 8, if they're not abused!), assuming 250 cycles at 80% depth of discharge. Add these sets of batteries in parallel for increased amp*hours. Each set (or each battery) is rated at 225 amp*hours.

The local solar power handy man estimated a lifespan of 4-5 years here.

Obviously lifespan of batteries does depend on how you use your solar system. But for solar power to become more widely used and eventually the norm(!), it must involve as less changes in life style as possible.

12 volts fridges that have been developed (not only for camper uses, but also for normal household use and size) is one example of how you can maintain your normal lifestyle as much as possible while being off the grid.

What is needed, is solar systems that are as powerful and efficient as possible together with appliances that are adapted for being used in these systems.

But at the same time, it must be clear that the production and maintenance of these appliances and the renewable energy system itself does not take so much energy and/or create so much pollution, that the overall environmental gain is lost or only minimal. (Hence my questions on the batteries).

(check out this article to see that sometimes you feel you are being "green", but you are actually not:
http://blog.wired.com/cars/2008/05/the-ultimate-pr.html)

You need Martin...where is he?

I disagree that for solar systems to become the norm, then peoples lifestyles will have to change as little as possible. This is not a question of choice....oil and gas are running out, before they run out prices will (and are!) hit the roof. When you can´t afford a "normal" lifestyle, you can´t live one. Period.

Why not check out Nev´s article on the pot-in-pot fridge as a low-tech alternative to the 12v fridge....

Another bit of advice I was given, was to avoid all items which use electricity to create heat.....it is incredibly inefficient and there are always alternatives.

It's something I've been wondering about since my boss has been telling me that solar hot water panels have only a five year life - which makes the ongoing (initial instalation, management and also replacement) cost quite considerable compared to using piped fuels

I'd love to have all heating and power provided by sunlight and renewable fuel but I've realised I'm not rich enough

It's something I've been wondering about since my boss has been telling me that solar hot water panels have only a five year life

.

Where did your boss get the idea solar panels only last five years?. There are systems in several village's near me that have been around and working twenty plus years.


Tony

Clara wrote:You need Martin...where is he?

I disagree that for solar systems to become the norm, then peoples lifestyles will have to change as little as possible. This is not a question of choice....oil and gas are running out, before they run out prices will (and are!) hit the roof. When you can´t afford a "normal" lifestyle, you can´t live one. Period.

Oh, sure, you're right about that. Once the prices really hit the roof, there's no question about it. And although they are rising rather rapidly, until they really hit the roof, people will NOT want to change their lifestyle but want to hang on to it as long as possible.

Clara wrote:Why not check out Nev´s article on the pot-in-pot fridge as a low-tech alternative to the 12v fridge....

Another bit of advice I was given, was to avoid all items which use electricity to create heat.....it is incredibly inefficient and there are always alternatives.

True, we never use a coffee machine, iron or electric oven. Anything with heaters asks to much wattage.

But what, for example is an alternative to a coffemachine, apart from simply cooking the water on the gas (just like everyone does for tea, b.t.w.)?

Turtuga Blanku wrote:But what, for example is an alternative to a coffemachine, apart from simply cooking the water on the gas (just like everyone does for tea, b.t.w.)?

One of these?

http://it.wikipedia.org/wiki/Caffettiera

how does it work? (My Italian is er.. quite bad..non-existent). (I don't drink coffee, b.t.w., but it is still interesting to know of good alternatives to tell other people about)

also, if anyone has any information on the original topic of this thread, don't hesitate to contribute! :)

They are very simple to operate and the coffee tastes much better than from a perculator or one of those plunge caffatier type things.

They cup in a variety of sizes from 1-10 cup, most Italians have a selection depending on how many they are making coffee for. You fill water up in the bottom half to just to valve level. then fit the middle bit and fill with ground coffee. Screw the top on and place on hob. Coffee is ready when it starts to gurgle (it does this just as the last coffee spills out of the spout).

Electricity : In the UK the appropriate way to utilise PV is to be grid connected that does away with the need for batteries and ensures a supply in emergency conditions ...

...can't comment on the rest of the world.

Solar Hot Water is undoubtedly and indisputably 'environmentally friendly' ...

mybarnconversion wrote:Electricity : In the UK the appropriate way to utilise PV is to be grid connected that does away with the need for batteries and ensures a supply in emergency conditions ...

It doesn't. If you're grid-connected without batteries, you have no electricity in power cuts.

I found some info on batteries that are used in EV (Electric Vehicles) which are often similar to the ones used in solar power systems:

Aren't the dead batteries a hazardous waste?

No. Batteries are 99% recyclable, and are one of the most highly recycled products in the country. When you buy a new battery, the dealer will ask for your old ones in trade, or you will be charged a "core charge" if you don't turn them in.

( http://www.electroauto.com/info/poll.shtml )

In addition, I found a nice article with the title:

Can Solar Cells Ever Recapture the Energy Invested in their Manufacture?

You can find it here: http://www.csudh.edu/oliver/smt310-hand ... ayback.htm

Take into account that this is an article submitted in 1997, and I think we can assume that technology has become even more efficient the past 11 years.

I must add that this article does not seem to take batteries in account...