SLO County PV Estimation for 2050 Group 1 John Carlin Chris Day Hyung Joon Kim Gordon Lai Alvin Tran Yat Tam

Overview  Model of our estimate includes –Population number P –PV technology efficiency E –Declining cost factor C –Storage Cost Estimate S –Financing Cost F  Conclusion

San Luis Obispo County

Population  Total size of 3304 square miles  In 2003, population in SLO county estimated is 253,118  Population growth rate from April 2000 – July 2003 is about 2.6%. Roughly speaking, the annual growth rate is 1%.  Based on the 1% population growth rate, in 2050, population in SLO county estimated is 404,043

Energy Consumption  Energy Consumption in U.S. per capita –Coal: 3.65 tons/person –Electricity: KWh/person –Geothermal Power Use: 0.01 per 1000 people –Hydroelectricity: 0.88 TWh/1 million people –Natural Gas: cubic ft/person –Nuclear Energy: 2.82 TWh/1 million people –Oil: barrels per day/per 1000 people

SLO Energy Use Exajoules

What are solar panel prices and where are they headed?

Yesterday:  Trend of solar panel price index over the last 4 years is generally decreasing  Price index is volume weighted toward the high density (>125Watt) solar panels Solar Panel Prices, Today and Tomorrow Price index is for single panel quantities

Today:  Index cost is $5.00 per watt  Increased $0.01 per watt from last month  September had 499 modules below $4.50/Watt  Lowest cost crystalline module is $3.50/Watt  “Very large volume purchasers” can secure prices around $3/Watt Solar Panel Prices, Today and Tomorrow

Tomorrow: (The forecast is sunny…….)  An Exponential projection indicates 35¢/Watt cells by 2050  Breakthroughs (or lack there of) in solar cell technology will significantly effect the cost of solar panels over time Solar Panel Prices, Today and Tomorrow

Current Efficiency Current Technological status of the photovoltaic technology  Photovoltaic (PV) is the direct conversion of sunlight into electricity using devices made of thin semiconductor layers. Silicon technology is the most mature and a crystalline silicon cell can convert up to 23.5 % of the sunlight in electricity. Cheaper cells made of amorphous silicon actually have stable efficiencies of 7 %.  The area related component (structure, cabling, etc) cost represents from 35 to 60 % of the total cost of a photovoltaic system depending on the application. Power related components (inverters, batteries,...) can represent 16% of the total cost of a photovoltaic system.

Future Efficiency Prospective analysis of the photovoltaic technology  Technical aspects: The majority of experts have responded that the efficiency of the photovoltaic cells will be 95% of the theoretical efficiency sometime in the period  A flat crystalline silicon module will reach to 23 % of efficiency by the year 2050 and its lifetime will be up to 35 years. The crystalline silicon photovoltaic panels are already reliable (reliability more than 98%) and the thin film silicon and non- silicon modules will be in the period  According to the R&D status, experts thought that USA is in the first position and Europe and Japan are in the second and third position respectively. The expectations of the experts for the R&D status of these three regions are that they are going to achieve the same R&D level by the year 2020.

Storage Cost Estimation Available Storage Technology  Pumped Hydropower  Compressed air energy storage (CAES)  Flywheels  Superconducting magnetic energy storage (SMES)  Supercapacitors  Batteries

Why use batteries?  Power quality assurance  Transmission and distribution  Voltage regulation  Load leveling  Respond well to instant voltage spikes or sags and outages  No emissions, solid wastes, or large amount of leakage  Almost all battery materials (lead, acid, plastic casing) can be recycled.

Energy Storage Est. System Cost

Battery Technologies  Lead-Acid Batteries  Valve-Regulated Lead-acid (VRLS) Batteries  Advanced Batteries ($275/Kw) –Lithium Ion –Zinc/bromine

Storage Price Estimation  72.6% of total energy consumption are to be stored in battery .131 Exajoules used in year 2050  Exajoules needs to be stored  (1KWh = 3.6 MJoule)  *(10^10 KWh/year)  X = (2.6418E10)/(12m*31d*24 h) KW  (X KW) *($275/KW) = $ Billion

Funding Assumptions  5% interest rate  10 year repayment loans  Exponential energy usage  Exponential cost reduction

Installation Plan

Cost of Power

Cost  Installation cost: $ 19.2 Billion  Maintenance cost: $4.4 Billion  Batty Cost: $.814 Billion  Total cost with loans: $39.3 Billion  Total cost per person: $ 108,081.44

Conclusion  Installing the whole system upfront is costly without the long term benefits  Improvements in panel MTBF are as important as improvements in efficiency  Acceptance of HVDC for transmission can lead to significant savings by eliminating inverters in favor of DC-DC converters  Long term less expensive than PG&E