IEEE Power & Energy Magazine - May/June 2014 - 30

Smart vehicle charging strategies will be critical to avoid
potentially dramatic increases in generation, transmission,
and distribution capacity requirements.

drop in new wind projects. While many states have renewable portfolio standards, it is not clear if the targets will suffice for continued wind power growth.
Like wind power, the value proposition for solar also
relies on policy support in the form of feed-in tariffs in some
european countries, an investment tax credit in the united
states, and various state-by-state policies ranging from
tax credits and renewable energy certificates to net metering policies to renewable portfolio standards. each of these
policies strengthens the value proposition for solar power.
it is expected that strong policy support will continue to
drive new wind and solar power in the united states. and
as solar Pv technology rapidly rides down the cost curve,
solar power will continue to become more economical. solar
Pvs have seen explosive growth in the united states over
the past year or two, with Pv capacity installations exceeding wind in 2012. in some parts of the united states, solar
Pvs are on a trajectory to become a significant resource in
the generation mix. Wind and solar power continue to grow,
even as load growth has slowed. slow load growth in north
america and europe, and lower natural gas prices in north
america, are challenging the economics of wind and solar

Electricity (US$/kWh)

Gas (US$/gal)
4 6 8 10
Net Present Value
(EV-ICE)
US$10,000-$15,000
US$5,000-$10,000
US$0-$5,000
-US$5,000-$0
-US$10,000-$5,000

Better
Value
for
PHEV

Vehicle Cost

PHEV

Hybrid ICE

US$35,000

US$30,000

Fuel Economy 35 kWh/100 mi

51 mi/gal

10,000 mi/Year, 2% Interest Rate (Car Loan)

figure 3. Break-even economics for a hybrid ICE and a
PHEV. The maintenance costs for each vehicle were assumed
to be equal. (Used with permission from "Integrating Electric
Vehicles into the Power System," 2011 CIGRE Symposium).
30

ieee power & energy magazine

power. also, the subsidy to retail Pvs provided by net metering policies is under increasing challenge as it inherently
involves the transfer of costs to non-Pv customers. in the
near term, policy support is needed to maintain growth for
both wind and solar power.

Gas-Fired Generation
as both wind and solar resources increasingly constitute a
significant portion of the generation mix, questions have been
raised about the capabilities of the grid to manage the variability and uncertainty of wind and solar power. numerous
wind integration studies have been completed over the past
decade, led by groups like the national renewable energy
Laboratory, various utilities, state commissions, independent
system operators, and regional transmission organizations,
with each examining the performance and economic impact
of integrating high levels of wind power in different regions
of the world. a summary of the wind and solar integration
studies that Ge has led or contributed to is shown in Figure 2.
these studies suggest that integrating enough wind power
to generate more than 30% renewables by energy is possible, provided the system has adequate generation flexibility, transmission capacity, control area cooperation, and grid
requirements for wind plants, to name a few. however, the
capacity value of wind power remains relatively low, depending on the geographic diversity of the wind power plants, the
size of the control area, and the strength and nature of the
wind resources. the uncertainty and variability associated
with wind and solar power demands flexibility from the rest
of the generating fleet. Flexible generation will be needed as
wind and solar plants are built out. Faster starting times, the
capability to back plants down further, and higher unit ramping capabiliies are emerging as key needs to support the build
out of significant levels of wind and solar power.
as the economics for recovering unconventional natural
gas improve, north american natural gas prices are expected
to remain relatively low. the relatively low gas prices and
the potential retirement of significant levels of coal-fired
generation over the next decade will further promote the
build out of new natural gas-fired generation. Wind, solar,
and gas-fired generation will play a substantial role in the
grid of the future.

Electric Vehicles
evs and plug-in hybrid evs (Phevs) are slowly emerging as
alternatives to conventional gasoline-fueled vehicles but will
may/june 2014

Table of Contents for the Digital Edition of IEEE Power & Energy Magazine - May/June 2014