9 replies to this topic

[greenking]

Which is the best renewable source for you?

[still learning]

greenking, on 02 March 2012 - 09:00 AM, said:

Which is the best renewable source for you?

Not sure what you mean by best.

From a website for the utility we get our electricity from http://www.pge.com/a...ge/cleanenergy/
Looks like almost 16% of the electricity we get comes "eligible renewables," and over 15% from large hydroelectric and almost 24% nuclear.
Of that 16% renewables, 30.5% comes from geothermal and 0.5% from solar, 24% wind  and 18.3 small hydro.
30.5% of geothermal is 4.9% of the total
Not sure what you mean by "water."  Add the large hydroelectric and the small hydro and you get 18.5% of the total.

Of solar/water/geothermal which is most important to me personally now? Water/hydroelectric.

That'll change though.  I expect I'll eventually have PV on the roof, so that'll probably be personally the most important then.

It's in the cards that California's electricity will be "decarbonized" in time.  Large hydro can't be expanded, no new places to put large dams in.  Large scale geothermal expansion is pretty questionable.  Right now we actually get a fair abount of geothermal electricity but that particular resource is becoming exhausted.  The naturally occuring underground steam in being depleted.  There are efforts to inject water back down into the hot rock, but it's unknown how successful that will be in renewing the resource.   http://en.wikipedia....iki/The_Geysers .  Producing geothermal electricity from ordinary non-volcanic areas seems pretty questionable.  Don't think it's yet been shown to be practical.  May never be practical.  Or then again it may.  
Wind will be expanded, as will PV and thermal solar.
I kind of think we'll eventually see more nuclear electricity also, but not any time soon.

[E3 wise]

I think this goes to show that there is no one fix for alternative energy.  Luckily it seems that the  administration is getting the message as demonstrated by their announcement called President
Obama’s new- All-of-the-above energy policy, which seeks to cut oil, coal and natural gas subsidies, and tax loopholes while increasing incentives to Alternative Energy.  Now the only question is if the American People will notice and if the Congress even cares, we will see.

[still learning]

E3 wise, on 03 March 2012 - 05:04 PM, said:

I think this goes to show that there is no one fix for alternative energy.......we will see.

There is no single solution for our energy troubles.
From all i've read.
No matter what you mean by "our energy troubles."

Considering as an example the path to decarbonizing California's energy by 2050 as referred to in the third entry of this thread:   http://www.altenergy...change-efforts/
it'll take a lot of effort in many areas over decades to do the job.  It'll take a lot of conservation and energy efficiency.  A huge part of the problem is that transportation emits a lot of CO2.  A lot of motor fuel gets used.  Electrification of a lot of transportation is the main answer there, lots of battery electric cars and lots of plugin hybrid cars over the years.  So the path to low CO2 emissions by 2050 means not only replacing today's fossil fuel electric powerplants with either renewables or nuclear or CCS fossil fuel but installing enough extra to take the transportation load too.  And allowing for population growth.
It'll take some mix of lots more solar and wind and maybe other renewables too as well as either/or nuclear or CCS to do the job.  I haven't yet seen a believable scenario where renewables alone could do the job by 2050.

The path to decarbonization of our energy will be different in different places.  Maine doesn't have the same solar resource as Arizona.

[MyDigitalpoint]

I have always been a solar energy enthusiast, so I'm always seeking the way to implement solar panels for heating water and food, substitute electricity and everything else.

Water energy has been always associated to electric power stations, but water is not a renewable source at all and the proof are all those rivers diminishing their water volume each year with many extinguished already.

[still learning]

MyDigitalpoint, on 05 March 2012 - 02:42 PM, said:

......but water is not a renewable source at all and the proof are all those rivers diminishing their water volume each year with many extinguished already.

I don't understand.
What rivers extinguished?

The water in rivers is renewable.  Rainfall replenishes rivers.  Even those watercourses here in the US west that diminish in flow or even dry up every year during the summer dry season are renewed in the following wet season.  
River water resources certainly aren't without limit, but within that limit rivers are renewed.
Here in the US west there isn't enough river flow to satisfy all the different users and there is one major river, the Colorado, that doesn't always flow to the sea anymore because of withdrawals, mainly irrigation, but rain and snow does keep things going.

Rivers diminishing in water volume?
Do you mean because of drought or because of withdrawals for human use, irrigation and domestic use?  Droughts come and go, always have and they do affect river flows.  Droughts are even increasing some places, the US southwest being one place, but the world's total rainfall remains about the same.  If anything climate change/global warming is expected to cause the hydrologic cycle to move more water around:  http://en.wikipedia....iki/Water_cycle

Some water resources like some aquifers aren't renewable, at least on a human timescale.  We do have a problem in some parts of the US with aquifers being depleted faster than they are being recharged.  Basically fossil water is being pumped out of some aquifers for irrigation or domestic use.  Little or no recharge of some aquifers her in the US west.  Those aquifers being drawn down don't provide water for hydroelectricity though.

Sometimes hydroelectricity isn't included in reports and articles as "renewables" electricity, instead is included as a category of it's own or is included as "conventional" electricity, which it is.  Hydroelectricity isn't "alternative" but is renewable.  As a practical matter hydroelectricity can't be expanded much in the US because the suitable sites are already used up.

[joeldgreat]

I think every aspect of these alternative sources will have an advantages as well as disadvantages. I think the worst of these three is the water sources. Hydro electric power plants do have negative impact to the environment. Contruction of the dam alone will surely displaced many living things and will distured the ecological balance. Geothermal power plants is I think will release harmful gasses which comes with the extraction process to the environment. That leaves solar power to be the best source of alternative energy for me. But with a higher cost, I think.

[CryoMage]

The idea of a building or a house powered only through a geothermal source beneath it has always intrigued me. The pseudo-random water jets which come out at a very high pressure could be used to power a small hydro-generator. Not to mention the hot water from the source would negate any need from and external heating solution. The only problem is the usually geologically unstable ground which hosts the geothermal sources.

[still learning]

joeldgreat, on 09 March 2012 - 05:52 PM, said:

. Geothermal power plants is I think will release harmful gasses which comes with the extraction process to the environment.

Some harmful gasses do come up out of the ground with the steam, but they don't have to released into the environment.

Can be captured and either reinjected back down into the ground or even converted to useful products.
http://www.geotherma...-usa/index.html
http://ntrs.nasa.gov..._1975012787.pdf

[dziomek]

I think given where I live, a combination of solar and wind power would be sufficient to supply our home with power and heat for the majority of the year. We do have some very cold winter temperatures, but that is where wood or pellet stoves come into play. I would like to build a cabin to test it on a small scale, and if it works well I would then incorporate it into a larger home. We have a supplier of solar and wind power systems in a neighbouring town, so I would also be supporting the local economy by purchasing the system from him.