Europe is going to leave us in the dust unless we have a comprehensive solar/wind/geothermal energy strategy in place very soon. We need to recognize the insane amount of $$ that we are burning with coal and oil.

The big problem is cost/watt and storage. Currently PV's are at around $4/watt (for a 1kw/m^2 panel I believe). Storing the energy for later use is still a huge issue.

Exactly. PV panels are great... *IF* you have an energy storage solution that is cheap, safe, environmentally friendly, and small. So far we have zero out of 4 of those requirements met in our current energy storage systems. Yay.

I just wanted to echo the above comments: STORAGE. STORAGE. STORAGE.

"FREE" "UNLIMITED" energy is everywhere. How do you save it?!

Hello ... Solar doesn't work in the dark and there are no global interconnects. Solar power can never be baseload. It is only useful for peak power applications. Ask anyone in a public utility if you want the truth which the proponents of solar will never give you. Sorry to burst your bubble.

"FREE" "UNLIMITED" energy is everywhere.

Well, all energy is free; it's just the small matter of extracting it, whether that's putting a straw through kilometres of rock to extract a sticky goo produced by heating of algae with the radioactive decay that keeps the Earths innards molten or building solar heat collectors, getting building permits...

As usual the devil is in the details.

Hello ... Solar doesn't work in the dark and there are no global interconnects.

Is anybody here arguing that solar works well in the dark? My father's does actually generate a bit of electricity at night, but I know that's the exception. What are you talking about when you say "global interconnects"? And why would we need them?

Solar power can never be baseload. It is only useful for peak power applications.

Present photovoltaic technologies could provide the vast majority of electricity used in the United States. In principle, it could also provide the world's energy needs, but I think we all know that would be a dumb goal. In practice, however, a combination of geothermal, wind, solar, and perhaps other untapped sources could most certainly meet nearly all of our energy demands.

Ask anyone in a public utility if you want the truth which the proponents of solar will never give you. Sorry to burst your bubble.

I see, the old argument from authority followed by the conclusion that you've burst our bubbles. The demonstrable truth that has been proven and ignored for decades is that renewable energy can displace fossil fuels and minimize our dependence upon them. The Enrons of the world benefit most from us maintaining the status quo, with middle eastern royal families coming in a close second. If this was EconOrg instead of PhysOrg I'd have to go into a long argument about what $3.8 trillion leaving an economy can do...

While we do have a lot of work to do, we need a huge investment to be made in the US to develop storage technologies and other improvements that benefit renewable energy.

And speaking of what is now currently available, Solar thermal does have a method that can be used so that it can generate electricity day and night. Essentially, some of the heat used to create steam to turn turbines is used to create molten salt, and then this salt is kept in a well insulated tank. During the night this heat source can be tapped to continue generating power.

While photovoltaics do need a lot of work regarding storage technology, whether it be batteries, creating hydrogen that is used in a fuel cell at night, or otherwise, I think solar thermal is a lot closer to being a viable 24 hour power source that should be heavily looked into.

Yes solar thermal is viable. Unfortunately, in California, where it is being built, the environmentalists will not allow the construction of the power lines needed to bring it to the grid. They only give lip service to solar and wind. The environmentalists do not want any centralized power in this country.
We need all forms of energy here in the USA.

Solar energy IS the source of all but nuclear power. Solar energy is low quality/density energy limited by the Solar Constant 1350 Watts m^-2 or about 4 kW-h/day at high latitude.

You can collect all the Solar energy you will with an appropriately sized collector.

And, NO not peak power. That must be high density power.

What are you talking about when you say "global interconnects"? And why would we need them?

When the sun isn't shining you must get electricity from some other source. That second source can either be oil, gas or hydro(limited availability) peaker plants, expensive storage(just the storage is more expensive than coal or nuclear generation), spinning reserve coal or very long HVDC lines to somewhere the sun is shining.

It cannot be wind power. Because wind power is even more unreliable and may be in need of backup as well.

In practice most "wind farms" get most of their energy from coal and gas.

The demonstrable truth that has been proven and ignored for decades is that renewable energy can displace fossil fuels and minimize our dependence upon them.

What's been proven is that renewables are very expensive, very unreliable and very diffuse. Much of the cost is not in the generation(though that is quite awful when you account for the low capacity factor, especially for photovoltaics); it is in the transmission(diffuse means lots of power lines; unreliable means lots of very long power lines), and in storage(e.g. you need to convert it into hydrogen gas, ammonia or charge batteries to power a vehicle).

Solar energy IS the source of all but nuclear power.

Not quite.

Nuclear fission and geothermal are kinds of solar energy but not from our sun. Heavier elements than iron-56(such as uranium) can only be formed in extremely violent process such as a supernova.

Geothermal energy relies on the radioactive decay chains of thorium, uranium-235, uranium-238 and potassium-40.

Nuclear energy relies on splitting atoms, which increases the nuclear binding energy per nukleon and thus releases energy(for elements lighter than iron-56 the opposite is true and you need to fuse atoms toghether to release energy).

Nuclear fusion however uses primordial hydrogen and lithium(to produce tritium); when you do that on Earth it is not a kind of solar energy.

Coal is the answer. We have mountains, and mountains, and mountains of it. Coal is getting cleaner and it's cheap. It's the only way to boost our electrical supply fast enough to prepare for the upcoming onslaught of plug-in hybrids. More to the point however, powering our fleet of cars with clean-coal made electricity will reduce pollution(Not that I believe the global warming Hoax anyway).

All these comments are useless. Unless you're an expert in the field you should STFU.

There have been plenty of articles on this site about new technologies being developed to store solar energy, more efficient ways of converting solar energy, etc.

So the answer to everyone's "how are you going to do ___?" is very complicated, not in the sense that it's not feasable, but in the sense that if someone was to tell you the answer you high schoolers wouldn't understand. So don't bother asking, there are smart people out there who have and will solve all these problems.

"unless your're an expert" LOL, all these experts keep talking about megawatts and
global interconnects.

funny that given your average person just wants to power their single device, be it the LCD monitor, the low power mini PC and/or the wireless router.

what these Photovoltaic Solar Energy conference and related so called experts should do is stop thnking large and think small, its simple
produce a global power socket that any new energy device can connect to and give out a basic 5V/12V 1 watt and make every single new electronic device use that socket.

we NEED single self contained power units that can connect and poer these everyday LCD and PC items and we need them today.

when i can go down my local shop and buy these self contained PV storage devices and plug it directly into my LCD and mount the unit on the windowsill then we will be somewere near what real people care about, spending a one off cash outlay to save paying real cash to charge your electric meter every week.

the current trend of the PC world markets have it right , lower the watts per hour on all the new mini PC intel Atom processor, 8.9-inch LED display and other devices, http://www.dailyw...with-3g/

http://www.dailyw...o-watch/

and wireless kit.

peopel just dont care about billion kilowatt plans to make money for world business,or feeding any spare power generation back into the current grid, they care about powering their PC kit in the home and gardens, and saving real money week on week, give them that in a self contained unit and they will buy a unit a week until they have enough to power all they want down the local shops.

ww already know one single option isnt enough to cover everything so give me a direct universal interconect on all the devices and give me PV for the day, mini wind for the night, and Fuel cells for anytime of the day or night
http://www.h-tec....p?id=314

Solar energy IS the source of all but nuclear power.

Not quite.

Nuclear fission and geothermal are kinds of solar energy but not from our sun. Heavier elements than iron-56(such as uranium) can only be formed in extremely violent process such as a supernova.

Geothermal energy relies on the radioactive decay chains of thorium, uranium-235, uranium-238 and potassium-40.

Nuclear energy relies on splitting atoms, which increases the nuclear binding energy per nukleon and thus releases energy(for elements lighter than iron-56 the opposite is true and you need to fuse atoms toghether to release energy).

Nuclear fusion however uses primordial hydrogen and lithium(to produce tritium); when you do that on Earth it is not a kind of solar energy.

You pretty much confirmed what he said - fission and geothermal - stellar energy (but not solar), fusion - primordial energy, both of you missed one source though...

Tidal energy which comes from the Moon :P

Tidal energy which comes from the Moon :P

Come on. If there wasn't a Sun there wouldn't be an Earth or Moon... ;-]

All these neg arguments are crap. If we only have cow fart to depend on for energy, someone would find a way to use it on a global scale. It's all about money and will, not a technological dead block. That's what i despise about humans, although unfortunately i am one!

Not quite Soylent. Geothermal is partially fission, and partially the leftover heat from Earth's aggregation. So it is actually partly gravitational potential energy stored in the form of heat under heavy pressure and insulation (silicates surrounded by vacuum (space)).

And as superhuman mentioned, Tidal energy is created by the warping of Earth by Luna's gravitational field.

So we really have three sources of energy. Solar, Stellar (fission), and Gravitational Potential. Everything ultimately comes from either one of those sources, or as a hybrid (geothermal = Stellar and GP, Hydro = Solar and GP).

(Why can't I use a plus sign on here anymore?)

Doesn't matter I guess that there will be NO land to produce FOOD or bad weather preventing the already inefficient energy cells having less light to produce electrical energy.

Not quite Soylent. Geothermal is partially fission, and partially the leftover heat from Earth's aggregation.

Unless the relatively fringe hypothesis of a geo-reactor is true(could be confirmed by detecting fission neutrinos from the center of the Earth) it's not fission, it's radioactive decay.

Very little of it is gravitional potential energy from the formation of the Earth(William Thompson/Lord Kelvin did the computation as early as 1862; if the Earth started out as a molten mass it would have taken only 24-400 million years for it to cool to the current temperature).

And as superhuman mentioned, Tidal energy is created by the warping of Earth by Luna's gravitational field.

Oops; yes that's correct.

So we really have three sources of energy. Solar, Stellar (fission), and Gravitational Potential. Everything ultimately comes from either one of those sources, or as a hybrid (geothermal = Stellar and GP, Hydro = Solar and GP).

Four; fusing primordial nuclei.

We even know a way to extract useful energy from it too. You could tap heat from underground thermonuclear explosion in the same way you can geothermal energy, but it's not cheap(nor is it sane).

Why would someone need to store the energy from photovoltaics? Pushing it back to the grid would lower the energy demand of e.g. coal power plants at daytime, thus helping with the environment.

If you must store the energy, you could go from supercapacitors and batteries to hydrogen creation and water desalination.

Even funnier, since allowing the solar energy to reflect is causing global warming, if we trap all of this energy wouldn't we be causing global cooling by preventing the sun's energy from being able to heat the environment?

Say no to solar we don't want an ice age!!!

Now on a more important note, solar is really no good to me in the northern latitudes. As others have said, when it works it's great. When it's winter or night time, (when I need the most energy), it's not available, or only marginally available, due to the failure/lack of current storage methods.

I think in the next 10 years or so we'll see solar come into it's own, they've upped the max potential of solar cells to 40% or so which is pretty huge seeing as that's pretty close to coal/oil efficiency when you take waste heat into account, and recently there was an article on how scientists are getting very close to being able to replicate the photosynthetic process that plants use to store solar energy.

Solar is a great idea. I have PV's on my roof at the moment. I receive a tax break and on a hot midsummer's day it certainly helps take the edge off the electric bill while I run my central AC. The technology is effectively still in it's initial stages, if we can get the environmentalists to pick a side and stick with it then we can probably get some progress made in getting solar to a more feasible state.

Once again...if a portion of the PV's energy is used to compress air into huge underground "tanks" during the day, which are also heated geothermally, then that compressed air with its added energy potential can be used to turn turbines at night...providing electrical generation 24/7!

Once again...if a portion of the PV's energy is used to compress air into huge underground "tanks" during the day, which are also heated geothermally, then that compressed air with its added energy potential can be used to turn turbines at night...providing electrical generation 24/7!

At what sort of energy loss? The problem isn't the how, it's the how big and how efficient.

Current energy storage efficiency is far to low to make solar a viable technology. That and the amount of air you'd need to compress to make your system viable is extraordinary. I don't see anyone drilling a 40 foot shaft underneath their house to store energy.

Once again...if a portion of the PV's energy is used to compress air into huge underground "tanks" during the day, which are also heated geothermally[...]

Once again, that's asinine.

Unless you only plan to deploy your solution in Iceland you'll need hot dry rock geothermal. HDR is not ready for deployment and the economics are uncertain.

Instead of trying to dress up a pig with geothermal energy, why not use geothermal energy to directly provide heat and power if it is economical?

[...]then that compressed air with its added energy potential can be used to turn turbines at night...providing electrical generation 24/7!

That's more expensive than just getting baseload from nuclear or coal. Ergo the temptation is to use nuclear or coal unless given a very strong incentives to do otherwise.

In the real world only two large scale CAES plants exist, Huntorf Germany(0.58 GWh, 290 MW) and McIntosh(2.86 GWh, 110 MW). Both use the compressed air to avoid the compression stage of a natural gas turbine. McIntosh is newer and much more efficient; it uses 1.17 kWh of natural gas and 0.69 kWh of compressed air to produce one kWh or electricity. I.e. only 37% of the power it consumes is from compressed air.

As for efficiency; a modern combined cycle natural gas turbine is ~55% efficient. 1.17 kWh of gas is equivalent to 0.64 kWh of electricity. If you count the other 0.36 kWh as comming from the compressed air the McIntosh storage is only ~52% efficient.

Why would someone need to store the energy from photovoltaics? Pushing it back to the grid would lower the energy demand of e.g. coal power plants at daytime, thus helping with the environment.

It takes about a day to start up or shut down a coal plant. You can however disconnect the generator completely from the grid if you have ~1 GW of solar power; that will allow the coal plant to act as spinning reserve; it won't produce electricity and it will burn a bit less coal to keep the turbine spinning and synchronized with the grid. The solar farm people will of course have to pay the coal people at least as much as the profits they forgo by not generating as much electricity as they could; otherwise there's no compelling reason for them to even think about it.

If you must store the energy, you could go from supercapacitors and batteries to hydrogen creation and water desalination.

Supercapacitors are excellent for power conditioning but they've got lousy energy density. Batteries are too expensive for grid power. Hydrogen gas is difficult to store and transport and hydrogen fuel cells are expensive; perhaps run it through haber-bosch and produce ammonia instead of electricity? Desalination of water is only a useful energy sink for unusable electricity in places where water availability is an issue.

from an Ordinary Users POV pushing it back into the grid just moves it around without good reason.

if your Ordinary Users are not using 100% of their PV energy units in low voltage devices and 12V-240V Power Inverters then they are potentially not using any grid power eather and so as the % rises less grid power is required anyway, and so the auto regulated powerplants systems will just power down to that new lower level as they do now in the night time.

sure, using any stored PV energy in your supercapacitors and batteries or any other means, to also produce hydrogen creation from distilled water when it suits your needs.

and again locally storeing this hydrogen for your home needs for later use for your higher power delivery Fuel cells for anytime of the day or night is a good thing
http://www.h-tec....p?id=314

its going to need one of those low power PCs to run it all and regulate the seperate self contained units for best energy/storage production over the 24 hour day and allow for easy additions as your home needs grow OC.

soylent said:"Supercapacitors are excellent for power conditioning but they've got lousy energy density.

Batteries are too expensive for grid power. Hydrogen gas is difficult to store and transport and hydrogen fuel cells are expensive;"

well the newest nano capacitors seem like they could easly reach todays energy densitys and way beyond soon enough, alas it not here on your table today and thats a shame but soon perhaps.

http://www.physor...217.html


"Hydrogen gas is difficult to store and transport and hydrogen fuel cells are expensive;"

notaccording to this german company thats been producing plastic encased stackable units for kids school science kits for a long time now,and they will sell you base kit for industrial/home prototyping and then produce these units in gross No.s if you pay them the going rate TODAY.

dont you have something like this company in the US ?.

3 ways to store just enough for your personal home use can use any of these
http://www.h-tec....p?id=313

http://www.h-tec....p?id=314

http://www.h-tec....p?id=315

http://www.h-tec....?id=221-
"Solar hydrogen technology demonstration system, designed for extended, unsupervised operation, consisting of PEM electrolyser, water tanks and PEM fuel cell.
Accessories such as Solar Module Premium, electric load Fan, lamp Videolight, PowerSupply 4 mm, cables and textbook included. Specifications
Electrolyser: 10 W
Fuel cell: 1.2 W
Solar module: 2.0 V / 1.0 A
Power supply: 5.0 VDC / 1.2 A
Fan: 10 mW
Spotlight: 300 W
H x W x D: 650 x 800 x 300 mm
Weight: 6.6 kg

"

http://www.h-tec....ndex.asp
"
h-tec was founded in 1997 in Luebeck, Germany, and has become a leading supplier of educational fuel cell systems and materials world wide. h-tec has expanded in 1999, founding a new division to apply its know-how to the production of commercial electrolyser and fuel cell systems. This second division has already produced its first prototypes PEM electrolysers and low power PEM fuel cell stacks. h-tec is looking to collaborate with providers of commercial products in the integration of its electrolyser systems and fuel cell systems. Our aim is the production of PEM systems with the best cost/performance ratio in our principal market, Europe. We achieve this ambitious goal through the use of very cost-efficient materials and unique stack design.

Specifications EL 30
Hydrogen production up to 40 Nl/min (2.4 Nm³/h)
Oxygen production up to 20 Nl/min (1.2 Nm³/h)
Number of cells up to 55
Voltage up to 100 VDC
Current approx. 100 A
Power input between 180 W and 10 kW
Water consumption up to 3.5. l/h deionized water
Electrolyte Polymer electrolyte membrane
H x W x D Stack 55 cells 110 x 200 x 105 mm
H x W x D System 400 x 450 x 600 mm
Weight Stack approx. 2 kg

PEM Electrolyser EL 30

h-tec presented at Hanover Fair 2008 the latest prototype of its PEM electrolyser stack. Electrolysers will become increasingly important as investments are made in fuel cell technology, because such an energy system requires a reliable hydrogen infrastructure. However, even with the current low demand for hydrogen, existing methods of both producing hy­drogen (usually from fossil fuels) and transporting it (usually in pressure bottles) are already show­ing their weaknesses. Future energy systems will require reliable, on-site gas production, and this is where electrolysers are uniquely valuable.

The h-tec system consists of an electrolyser stack, water supply and cooling, water recirculation, system management, and monitoring software. The designs of the individual components and the stack itself are optimized for high-quality serial production. Depending on your needs, h-tec can produce stacks with anywhere from 1 to 55 cells.
"

nothing to do with these germans, but they are doing this TODAY, those very small industrial units are cheap and could run many home appliances makethem into those self contained units and we already have a viable option and ready producedbasic building block to use it seems, dont the US have anything like these guys at this low price per unit?.

I don't know about you but all my appliances require a lot more than 1 amp to run. Especially my refrigerator, oven, stove, microwave, etc.

Basically what that german company is selling is a small car battery. Great, problem is the energy storage and life of the battery are terrible. They are far better than past solutions of the same vein but still not efficient enough or cheap enough to be employed in the home to any great extent.

Now when on the manufacturer's site the specs look good but how much does this system cost?

Power input between 180 W and 10 kW doesnt seem to bad for your max and way below the average single home OC, so calling the indusrial versions above car batterys is a little odd.

sure the kids toys on show are to low for most non portable kit, but they dasychain to produce very dense and yet powerful multi watt units even in the plasic school kits not showing them all today as they redid the website since i found them last year...

rathr i ment to say above your average home power needs per hour