Solar Power Management utdallas Page metinmetin/Merit/Folios/solarManage.pdf · Thermal →Wind: Solar Updraft Tower. 6 Wind is due to air pressure difference If hot air is collected

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etinPage 1Solar Power Management

Outline Harvesting Solar Power

Thermal Photovoltaic

Solar power economics and policies

Prof. Metin Çakanyıldırım used various resources to prepare this document for teaching/training. To use this in your own course/training, please obtain permission from Prof. Çakanyıldırım.

If you find any inaccuracies, please contact [email protected] for corrections.Updated in Spring 2019

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Feasibility of Solar Energy Now

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Harvesting Solar Power Sun’s energy can be harvested as thermal solar power and as photovoltaic solar power.

NuclearPower

SolarPower

ThermalSolar Power

PhotovoltaicSolar Power Electricity

Turbine

Direct Use ofHot Water

Thermal solar power capacity of 374 GW end of 2013, http://www.iea-shc.org/solar-heat-worldwide Installed thermal solar power capacity: China 262 GW; Europe 44 GW; US and Canada 17 GW.

Dwarfed photovoltaic capacity of 139 GW end of 2013, p.17 of “Global Market Outlook for Photovoltaics 2014-2018” published by Solar Power Europe http://solarpowereurope.org.

Wind

Steam

Oil recovery bySteamflooding

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Thermal Solar Power Thermal Direct Use: Solar power heats water that later is

used for heating buildings or to serve hot water needs. Thermal → Steam: Indirect Use to generate Electricity

(Concentrated Solar Power): – Collector absorbs the solar heat and passes to the water as it

passes through it towards the storage tank. – Storage tank keeps the water hot and insulated. A

secondary power source (electric or gas) can be used.– Hot water is used to generate steam for electricity turbines.– Collectors: Parabolic troughs (convex mirrors), Fresnel

concentrator (flat mirrors), dish stirling (dish shaped mirror).– Heat transfer agent:

» Water, which can be hard to come by in a desert. » Synthetic oil heated upto 735 F by convex mirrors,

Mojave Desert, CA. » Molten salt heated upto 1050 F in a tower by Sunlight

tracking mirrors. When power is needed molten-salt flows through a heat exchanger and cools down. Salt’s temperature drops at least down to 550 F, it has to remain molten.

collector storage tank

Sources: www.dipol.com.tr/solar_energy.htmwww.global-greenhouse-warming.com/solar-parabolic-trough.html

Ivanpah Solar Thermal Power Field

Focal point

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Thermal → Steam: Enhanced Oil RecoveryConvex mirrors track & focus sunlight on stationary pipes Water inside the pipes heat up and turn to steam Mirrors & pipes in a greenhouse to minimize heat loss

Mirror MirrorGlassPoint Solar Miraah facility, Oman

Challenge: Requires continues/strong sunlight Applicable between 40 degrees South & North Not applicable in Alberta

Greenhouse

Enhanced recovery by SteamfloodingSteam obtained from Solar power

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Thermal → Wind: Solar Updraft Tower Wind is due to air pressure difference If hot air is collected and fed into a tower, it will generate wind inside the tower while rushing to the top of the tower. This wind can operate turbines at the bottom of the tower. Air at the bottom can be warmed up with thermal solar power mirrors.

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2010 Jinshawan Tower, Inner Mongolia, China200-kilowatt power generating unithttp://news.xinhuanet.com/english2010/china/2010-12/27/c_13666710.htm

Challenges:– Cost & stability of a tall tower– Resistance of tower against strong winds

Solutions proposed a tower that– Is constructed from lighter materials, e.g., cloth– Floats, inflated with light gas– Bends to minimize the effect of strong winds

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Solar Power Area Requirement Overton, North Texas receives maximum irradiance of about 6 kW/m2 in August and minimum of about 2 kW/m2 in

December. Texas solar irradiance database is www.me.utexas.edu/~solarlab. Southwest US receives more solar energy about 6 kW/m2.

– Optimistically suppose sun is out 12 hours/day and 30% conversion efficiency, so we get 0.9 kW/m2

(=(6/2)*0.3) of radiation at every hour. How many m2 required to generate 350,000 kW (capacity of Mojave desert panels)?

» 350,000/0.9 = 388,888 m2 which can be made up by a 623 metre x 623 metre square. A (American) football field is 4,500 m2. About 90 football fields are needed.

– More likely scenario has sun out 8 hours/day and 20% conversion efficiency, so we get 0.4 kW/m2 of radiation at every hour. How many m2 required to generate 350,000 kW?

» 350,000/0.4 = 875,000 m2 which can be made up by a 935 metre x 935 metre square. About 200 football fields are needed.– Where to find such a large deserted land? In a desert!

Total US generation capacity was 1,000,000,000 kW in 2007, which requires 1,100,000,000 – 2,500,000,000 m2 or 250,000 – 560,000 football fields.

Source: http://sroeco.com/solar

Mojave desert 5000-6000 W/m2

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etinPage 8Roofs for Solar Power at UTD and around

In 2013, UTD installs 220 kilo watt solar panels on the new Parking Structure, see the photo below. With this, UTD was able to participate in a Solar Program funded by Oncor and qualified to receive $203,722.

UTD also qualified for another $98,371 in incentives during 2012 for efficient chiller installations and by constructing buildings that are more efficient than the code requirement.

This brought the total incentive in 2013 to $302,093.

Utility companies are required to invest in energy efficiencies in their service areas. – Oncor runs the “Take a Load off Texas” project, which funded $62 million in 2013.– CenterPoint invested $42 million in projects in 2013.

Source: Merit Report: Plugging into Energy Efficiency. 2014. Z. Cologlu, D. Flom, T. Junt, S. Patel and A. Pizaňa.

In Fall 2013, parking lotnorthwest of SOM building

ATT distribution center Lancaster, TX

In 2015, ATT installs 677 kilo watt ground mounted solar panels. 2,000 panels provide about 40% of building’s annual power need.

UTD’s Energy Revolving Fund reinvests these incentives in energy efficiency projects on campus. Savings from the projects refill the fund.

FedEx distribution center Hutchins, TX

In 2014, FedEx installs 1,400 kilo watt roof mounted solar panels. 4,622 panels provide about 20% of building’s annual power need.

~0.3 kW/panel

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Industry: Photovoltaic Cells Types

Efficiency of converting solar energy to electric energy can range from 7-13%: Thin-layer PV cells deposited on plastic (glass or steel). 14%: Low-end polysilicon 15-18% : High-end polysilicon made up of cleaner pure silicon wafers. 30%+: Gallium Arsenide PV cells used in the space program.

Types of Photovoltaic Cells Thin film solar cells, limited market share, low cost and efficiency Crystalline silicon

Monocrystalline: Crystallization starting from a single cell Polycrystalline: Crystallization starting at multiple cells

Impurities at boundaries Multi-junction: Multiple p-n junctions in tandem

Silicon wafers used in PV cells are as thin as 200 microns (10-6 meters) and about 15-20 square centimeters.

A PV cell is the building block producing about 1-2 watts. It is assembled into modules and arrays with serial connections.

Source: http://science.nasa.gov

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Industry: Photovoltaic Cells Global Production

Global production of polysilicon is 69,000 tons in 2009. Chinese production is 20,000 tons. Half of this came from a single company: GCL Poly. Polysilicon plants should have more than 5,000 tons of annual capacity to be competitive. A 10,000-ton

plant can cost about $1 billion. GCL Poly managers believe that the price should be about $28/kg; others suggest higher prices.

Revenue of 10,000 ton plant = 28*10,000,000 = $ 280 million US has competitive edge on thin-film PV production. Chinese firms Yingli and Trina are closing the gap.

PV and Module Production in 2009 Haley and Schuler (2011).

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etinPage 11PV Capacity, Supply and Demand

from Haley and Schuler (2011)

PV Installed Capacity in 2010 PV Overcapacity

Germany, Spain and USA are the first three in terms of leading installed capacity. Governments offer incentives to consumers to adopt solar energy.

In a FiT (Feed-in-Rate) contract a government pays consumers to reduce the gap between solar and conventional energy for extended period of time (20 years in Germany).

Germany introduced FiT subsidies in 2000 and has been reducing them. Spain introduced FiT subsidies in 2007 at about €0.45/kWh and reduced it by 35% in 2008 and also by

30% in 2010. Consequently, polysilicon price collapsed from its heights of $450/kg.

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etinPage 12Government Policies: Production and Consumption Assistance No production and no consumption assistance

– Solar is not cost-competitive without assistance.– Upstream (Production) companies: Consolidate or withdraw.– Midstream companies: Fierce competition →Acquisitions of midstream firms by production firms.– Downstream companies:

– Find non-traditional customers such as – municipal power companies – public utilities– residential users

– Have restrictions removed on widespread use such as limitations on rooftop installations in residential areas.

Production assistance but no consumption assistance– Production grows, upstream companies benefit– Midstream companies want to sell in the international markets– China’s experience– Solyndra case in US: Inability to compete with the manufacturing cost caused failure to pay $535 million

federally guaranteed loans. No production but consumption assistance

– All benefit from higher demand. – Upstream companies may want to stop import boom

– Use domestic content requirement as in Ontario’s to qualify for FiT. – Downstream companies should not be addicted to consumption assistance

– Expand demand: Net-zero affordable homes in Arizona, California, Colorado, Nevada– Spain’s experience

Both production and consumption assistance: Likely to be unnecessary

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etinPage 13Economics of Solar Power

Consumer’s Perspective

Scenario: The installation cost of panels at $8 per W and tax credit of 50% (consumption assistance).– The installation cost to generate 2000 W is $16,000. – Tax credit compensates for 50% of this cost so the consumer is left with $8,000. – The total energy generated by these panels: 100,000 kW – hour = 2 * 5.5 * 365 * 25

» 2 kWh per hour.» 5.5 hours per day: accounting for clouds, sun at the horizon twice during the day.» 365 days per year.» 25 years of lifetime for panels.

– If the retail price of electric is $0.08 per kW-hour, the saving over panel’s life time is $8,000.– Without 50% consumption assistance, consumers will not install panels.

The latest gains in efficiency is puling the cost down. Say $3 per W. Realizing this, the governments are reducing the tax credit. Say 30%.

Scenario: The installation cost of panels at $3 per W and tax credit of 30%.– The installation cost to generate 2000 W is $6,000. – Tax credit compensates for 30% of this cost so the consumer is left with $4,200. – The total energy generated by these panels: 100,000 kW – hour = 2 * 5.5 * 365 * 25– If the retail price of electric is $0.08 per kW-hour, the saving over panels life time is $8,000.– With or without 30% tax credit, consumers will install panels.

A 2,000 squarefeet house needs approximately 2,000 W of power.

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Roof-top Solar Panel Savings at UTD Go to http://pvwatts.nrel.gov and use UT-Dallas campus address 800 West Campbell Road, Richardson. Select the weather data for this location. The closest data location is TMY3 Dallas/Addison. Enter PV system information to obtain columns A and E below

Consider a 4 kW system with standard (polycrystalline silicon) module type. If modules are for residential use, they are most likely to be polycrystalline silicon.

A 4 kW system is likely to have 16 solar panels. With panels of the standard 1.6 x 1 m2 , we need about 30 m2 of roof space.

Most residential panels are fixed (as opposed to one-axis or two-axis sun tracking) on the roof. If your panel is facing south directly, the azimuth angle is 180 degrees. The tilt angle is the slope of the roof for fixed panels, you can put 20 degrees for the tilt angle in Dallas.

You can keep the default system loss of 14% for taking into account shading, soiling, wiring, etc.

Averages over

A:kWh/(m2*day)

B: 30*AkWh/day

C:Days/month

D: Input, B*C kWh/month

E: Output kWh/month

F: % Efficiency

Jan 2.76 82.8 31 2,566.8 284 11.06

Apr 4.55 136.5 30 4,095.0 433 10.57

Jul 6.69 200.7 31 6,221.7 591 9.5

Oct 3.96 118.8 31 3,682.8 379 10.29

Annual 51,112.5 5,216

Finally, the saving with electricity cost of $0.1 per kWh is $521 per year.

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Roof-top Solar Panel Costs Generic solar panel costs

PV components Cost $/Watt

Module 0.48

Electrical 0.40

Inverter 0.06

Racking 0.10

Labor 0.10

Miscellaneous 0.02

Total 1.16

Cost of 4,000 Watt panel is $4,640 Savings $521/year Time to recover investment: About 9 years

Can we really save $521 without storage (battery)? Tesla is selling solar panel-battery bundles!

20 years lifetime for panels 10 years lifetime for battery

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etinPage 16Consumer’s Perspective

Price of Electricity

Time-of-day electric pricing advocates for charging higher during the day when the demandis higher than during the night when the demand is lower.

If the retail price of electricity is $0.16 per kW-hour during the day as opposed to $0.10 when the panel is generating electricity, the saving over panels life time increases by 60%.

Without a consumption assistance but with time-of-day electric pricing, consumers will install panels.

Who offers time-of-day electric pricing in zip code 75080 in March 2012? Go to http://powertochoose.org, enter zip code, pick variable rate, companies include:

Veteran Energy, Pennywise Power, Southwest Power & Light, YEP, Mega Energy, Direct Energy, GexaEnergy, Reliant, Smart Prepaid Electric, Frontier Utilities, Bounce Energy, Just Energy, First Choice Power, Entrust Energy, Texpo Energy, Power House Energy, Stream Energy, Andeler Power, Nueces Electric, Payless Power, Ambit Energy, Texas Power.

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etinPage 17Summary

Harvesting Solar Power Thermal Photovoltaic

Solar power economics and policies

Based on - R.L. Nersesian. 2007. Sustainable Energy Chapter 9 of Energy for the 21st Centrury: A Comprehensive Guide to

Conventional and Alternative Resources.- U.C.V. Haley and D.A. Schuler. 2011. Government Policy and Firm Strategy in the Solar Photovoltaic

Industry. California Management Review, Vol. 54, No. 1: 17-38. - Solar Power Data and Insight by SEIA https://www.seia.org/resources