Solar Power

It’s coming of age

CSP (Concentrated Solar Power)

There are two types:Parabolic Troughs and

“Power Towers”

Parabolic Troughs

• Linear parabolic mirrors focusing light on a tube– Very efficient (60%) utilize salt heated to 1000 degrees– Insulated storage for salt– Then boil water, steam turns turbine, turbine turns generator.

Voila! 24 hour solar electricityalso– Most have a natural gas boiler integrated into loop, so plant

has full production 24 hours/day

Parabolic Trough

Another way to view a parabolic trough

Solar Trough “farms” in the US

“Solar One” Parabolic Trough in Nevada64 MW; 400 acres; (15,000 homes)

Nevada Solar One Schematic Diagram

Abengoa Solar Troughs

280 MW CSP with six hours of thermal storage under construction.

Near Barstow, CA ( equals 54,000 homes) completion 2014

http://www.abengoasolar.com/web/en/nuestras_plantas/plantas_en_construccion/estados_unidos/index.html#seccion_2

Greentech Mediafor the latest in . . .well, greentech

and from National Renewable Energy Lab—Thermal Storage

And the California ISO website shows demand and renewable output.

Solar One “Power Tower” in Barstow CaliforniaThe original solar power tower located in Barstow, California, and completed in 1981. The Solar One had a design capacity of 10,000 peak kilowatts, and was composed of a receiver located on the top of a tower surrounded by a field of reflectors. The concentrated sunlight created steam to drive a steam turbine and electric generator located on the ground.

PS-10 Power Tower in Spain

• Mirrors focus sunlight onto a small area at top of 300 foot tall tower. – Utilize liquid sodium as a fluid to collect and

transport heat to boil water, steam turns turbine, turbine turns generator.

– Power 65,000 homesIntegral is Sevilla PV, an integrated photovoltaic

array that will power 1800 homes

The PS 10, 11MW Heliostat Tower in Spain”

Hallelujah!

Ivanpah Power Tower—eastern California. First circle is nearing completion. 4000 acres. Towers 500 feet tall. 170,000 heliostats

(mirrors)390 MW Equals 140,000 + homes

$50 million to relocate endangered desert tortoises. There are desert ecosystems--no free lunches

But . . . Let’s not forget Photovoltaic—(Sunlight directly into electricity)

• Western PV panel makers driven out of business by Chinese• But, cheap panels make installation cheaper• Installation companies go crazy• Big investors see good opportunities• Solar City stock rises 200% in 2013

– Solar City model. Install homeowner PV systems for free, then take a portion of output to pay for systems.

PV still less than 1% of US power output, but increased 76% in 2012 bypassing wind for first time.

Solnova PV (Spain) in foreground=150 MWbackground PS-10 & PS-20 Power Towers

Agua Caliente Solar Project-Mojave Desert California. 290MW

Geothermal Energy

• Most common utilizes very hot water or steam. “The Geysers” in California.

• About 30 square miles active site.• About 1000 MW continual output.

Dry Steam and Flash SteamRequires very hot water/steam (The Geysers Model)

Enhanced Geothermal Systems:Got Hot Rocks?

• AltaRock Energy Inc. at Newberry Volcano near Bend.• Drill one hole into hot (600 degrees F) dry rock• Fracture rock by injecting cold water• Drill more holes about 1500 feet away• Pump water down original hole and out secondary

holes. Convert to steam and use flash (direct) or heat exchanger/binary systems to drive steam turbine and generate electricity.

• Successful test January 2013.

Enhanced Geothermal SystemUtilizing Hot, Dry Bedrock

Binary SystemUtilizes a secondary closed loop of low boiling point substance to drive the

turbine (Probable EGS model—low water consumption.

U.S. GeothermalNeal Hot Springs—Harney County

Binary System

• Utilizes hot water to boil secondary fluid in a heat exchanger.

• 23 MW Energy (perhaps enough for 26,000 homes)

• $136 million cost

Ground/Water Source Heat Pump Home Heating and Cooling

Benefits

• 50% - 70% more efficient than fossil fuel systems

• 25% - 50% less operating cost

Drawbacks

• Costs “Several Times” more than other heating/cooling systems

• Not many installers or repair/adjustment companies yet

Ocean Thermal Energy Conversion (OTEC)

• As Near as I can tell there are no operating systems utilizing the temperature differences in the ocean. In theory and in demos it works, but the costs are so high that nobody has yet invested in a commercial scale site.

In theory it is simple; in practice it is wildly expensive

Water Turbines (like wind turbines but tiny in comparison)

• Water is 784 times more dense than air = 784 times more energy per unit area of moving water.

• Dependable—tide goes in and out on a regular basis. Rivers flow at a dependable rate

• Widespread possibilities.• In reality, still in test mode—production costs still

very speculative.

Tidal Turbine

Marine Current TurbineWorld’s First Commercial Scale Tidal Turbine (Strangford Lough, N. Ireland)

1.2 MW capability (1000 homes)

Alstom Tidal Turbine—Orkney Scotland1 MW in tests (2013)

Christian Science Monitor articicle “Tidal turbines: New sparks of hope

for green energy from beneath the waves”

Ocean Renewable Power CompanyThis thing sits on the bottom of a river or bay. It’s a

demo and produces 150 kw of electricity as tide goes in and out.

Tidal Barrage SystemAdvantage is that this one can function as a “battery” saving impounded water to generate electricity later

La Rance Tidal Barrage in France-Built 1966240MW plant 26% efficient = 62 MW output

Sihwa Tidal Barrage, Korea, 2011256 KW, so a bit bigger than La Rance

Above the Surface

• Lots of Experimenting, no commercial examples yet—at least none that I know of, but here are some of the ideas.

Ocean Power Technology; PB150 Powerbuoy Exists. Potential =150 KW; output 36%= 54 KW

.

Lots of Ideas

Floats ride the waves moving piston up and down inside a magnet to make

electricity

Columbia Power “Stingray”OSU developed—makes no sense to me!

Pelamis Wave Energy ConverterOR Loch Ness Monster!

750 KW per monster. No commercial “farms” yet

Utilizing flowing air to turn turbine