530 likes | 536 Views
Thoughts on ENERGY. John Kramlich Professor of Mechanical Engineering Phil Malte Professor of Mechanical Engineering. QUESTIONS to ANSWER. US Energy: Where are we now? Where are we going? How about the local scene?. US Energy in Quads (1.0E+15 Btu). US Energy in Quads (1.0E+15 Btu).
E N D
Thoughts on ENERGY John Kramlich Professor of Mechanical Engineering Phil Malte Professor of Mechanical Engineering
QUESTIONS to ANSWER • US Energy: Where are we now? • Where are we going? • How about the local scene?
GASOLINE ENGINE EFFICIENCY Why? We ask a lot from a car
Hybrid Advantages • Ideal: Engine runs near one RPM and torque (engines oversized) • Regenerative braking • Hard acceleration covered by battery • Avoids big losses of city driving • Since wind friction goes with speed squared, highway mileage often lower than city (35 mph best!)
The Fuel Cell: An Externally-Fueled Battery
Platinum for cell Expensive machining Expensive membrane Auto: 35$/kW Fuel cell: 300$/kW Must find ways to get cost down or may not compete Fuel Cell Issues
Hydrogen Issues • Make H2 in fuel plant? Natural gas to H2 leads to a significant loss in fuel value (recover only ~60% of original energy). • Store H2 on vehicle? Safety? Space? • Make H2 from gasoline? Carry a chemical plant on your car?
Running Out of Oil? • Record of Consumption and Production in USA • Resource • Cheap versus Expensive Oil
Message • The supply of Cheap-to-Recover crude oil is limited – there is about a 40 years supply at the present consumption rate. • The world is becoming increasingly dependent on Middle Eastern crude oil. • There is a lot of Expensive-to-Recover oil – monetarily and environmentally expensive. • Should transportation move away from oil?
Simple Gas Turbine Fuel Generator Air Pump Hot Exhaust Burner Turbine
Hydropower Hydropower
Turbine/ Generator Set
Some Engineering Energy = g[mass of water thru turbine] X [height of dam] • Low reservoirs reduce effective height • Reduced river flows cut mass available • 300 W projection-TV operated for one hour = one ton of water through Grand Coulee Dam.
Malte 3500 ft2 Gas furnace, hot water, range-top Balance electric PSE Kramlich 2000 ft2 All electric Heat pump furnace SCL A Tale of Two Houses
Heat Pump • Heat is present in all air • But heat flows only from hot to cold • So heat in outside air won’t directly warm your house • Use electricity to “pump” heat from outside into your house • Better than just using electricity alone to get heat • Multiplies value of electricity
Message • Larger house requires more energy. • Electricity gives more heat (per unit energy input) than gas if a heat pump is used. • But: Electricity costs more, which is a reflection of its greater utility.
Solar PV? • Panel+BOS Costs = $750/kw-peak (grid-tied) • 12 kw System = $90,000 • Capacity Factor = 12% (20% in AZ) • Power generated = 12,600 kW-hr/year (Kramlich: 18,000-24,000, Malte: 11,000-15,000) • Simple Cost over 30 year life = 24¢/kW-hr • Arizona: 14¢/kW-hr
Vansycle Project: Wallula
Stateline Project, Wallula • 450 Turbines • 300 MW max • 70,000 homes