Page 72 - A Comprehensive Guide to Solar Energy Systems

Chapter 4 • Solar Power in the USA—Status and Outlook 67

State Spotlight: California is the world’s eighth largest economy. The state recently in-
creased its rPS to 50% by 2030, and on may 31, 2017, Senate Bill 100, which mandates
100% renewable energy by 2045, was passed and is likely to become law [25].
California currently generates about 35.66% of its electricity from renewable energy, of
which PV supplied 8.11%, large hydropower 10.21%, wind 9.06%, and biomass, geother-
mal, and small hydro the remaining 8.28% [23]. Coupled with its high average residential
−1
electricity price of 15.34 cents (kW h) , the state’s “Go Solar California!” Campaign has laid
the foundation for a thriving solar market [26].
Go Solar is a joint campaign of the California Energy Commission and Public Utili-
ties Commission, and includes various incentive programs to “encourage Californians
to install 3000 mW of solar energy systems on homes and businesses by the end of
2016.” The campaign provides online resources for installers, homeowners and other
stakeholders.
Go Solar is comprised of the California Solar Initiative (CSI), which is a rebate program
for customers of investor-owned utilities for PV, as well as thermal, installs. Incentive levels
are tied to anticipated and verified performance of solar systems, requiring careful energy
modeling pre-installation, and measurement and verification post-installation. A subset
of the CSI, the New Solar Homes Partnership (NSHP) provides incentives for new con-
struction and also requires detailed energy efficiency modeling and verification [27].
In addition to leading the nation in installed rE, California is helping fill the need iden-
tified in the Second Installment of the DOE QER for an improved understanding of the
electricity system through providing data points for modeling and analysis.

4.3 US Solar Energy Market Outlook

Note on Modeling—In the NREL SunShot, ITC and Renewable Electricity Futures Study
discussed in this section, two primary tools were employed for grid modeling and analysis,
reEDS and dSolar. The regional Energy Deployment System model (reEDS), “a capacity
expansion and dispatch model for the contiguous U.S. that relies on system-wide least
cost optimization to estimate the type and location of future generation and transmission
capacity,” and Distributed Solar (dSolar), “a consumer adoption model for the U.S. roof-
top PV market that simulates future rooftop PV deployment in the industrial, commercial
buildings, and residential buildings sectors” [28].
reEDS accounts for location-dependence, variability, and uncertainty of wind and
solar resources through high spatial resolution and statistical methods, and dSolar com-
bines a detailed representation of rooftop PV consumer segments with a county-level
representation to model geographic differences in rooftop PV resource and electricity
markets [28]. In addition, in the 2012 renewable Electricity Futures Study, NrEl used
ABB GridView to model hourly operation of the grid with high levels of variable wind
and solar generation [29]. The synergy of wind and PV in increasing the total renewable
energy penetration in the state of Ny was shown by another study by Nikolakakis and
Fthenakis [30].