Power off the GridPower off the Grid4

The Net Zero Energy Home

• Produces as much electricity (energy) as it uses.

• Net metering is needed to monitor energy generated by home.

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Balance

• Net Zero concept includes a balance of:– conservation– energy-efficiency – power generation

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Outlay vs. Payback

• ROI variable:– initial outlay– size of the system– available credits– financial incentives– local electricity rates

Initial costs are like

pre-paying future

utility bills.

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In My Backyard

• NREL calculator to estimate solar and wind savings –

http://pvwattsbeta.nrel.gov

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Back Up Systems?

• What happens if it is cloudy or not windy?– Stay connected to

the grid.– Store electricity in

backup batteries,– Use a generator.

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New Technologies, New Issues

• Wind turbines and solar panels challenges and changes:– Building codes– Clutter– Easements– Power grid capacity– Wind farms– Electric car recharging– Knowledgeable

technicians– Energy monitoring

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Where Does the Electricity Go?

• The average U.S. home consumes about 30 kilowatts of electricity a day.

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Net Metering

• Simple net metering– Meter spins backward to

give credit– Dollar-for-dollar credit

• Avoided-cost pricing– Requires an additional

meter at consumer’s expense

– Less than dollar-for-dollar credit

• Homeowner should confer with the insurance company about coverage for the equipment and liability.

What happens when a home generates more electricity than it can use or store?

What happens when a home generates more electricity than it can use or store?

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Solar Photovoltaic (PV) in Brief

• Components• Solar panel

placement• Tax incentives and

rebates• Information sources• Measuring electricity• Roof area calculator

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Solar Photovoltaic (PV)

• How Do Solar Photovoltaic (PV) Systems Work?

1. PV panels capture sunlight and convert to DC electricity

2. Inverter converts DC to AC power

3. Batteries store the power (optional)

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Making the Decision to Go Solar

• Project location• Capital outlay• Credits and incentives• Roof area and

capacity• Needs• Building codes• Scheduling the

installation

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Small Wind Turbine Power in Brief

12 Step Process1. Assess consumption and costs2. Reduce energy use where possible3. Estimate or measure wind resources4. Select model, size, height, and site5. Research incentives, rebates, credits6. Obtain zoning approval7. Complete interconnection agreement8. Obtain building and electrical permits9. Order turbine and tower10.Hire Certified Small Wind Installer11.Installation12.Commission the turbine

7 Criteria—Is Wind Power Right for You?1. Good wind resource2. One acre+ in a rural area3. Zoning and building codes

allow4. Can quantify energy needs5. Comfortable with long-term

investment6. Monthly electricity bills are

$150 or more7. Remote location without

access to grid

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Wind Power• Windmills then:

pump water• Windmills now:

Generate electricity– Advancements: Lower

wind speed requirements, smaller footprint

• Ideal for colder climates with limited sun

• Energy efficiency, not self-sufficiency

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Some Terminology to Know

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How Wind Turbines Work1. Wind rotates the turbine blades 2. Rotor captures the kinetic energy3. The motion drives the generator

which produces electricity. 4. The gearbox increases the

rotational speed between the rotor and the generator.

5. The yaw moves the rotor to align with wind direction.

6. The current travels through wires, from the turbine to the inverter.

7. The inverter converts the direct current into alternating current.

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Installing a Small Wind Turbine—Considerations

• Location and siting• Rooftop or vertical

systems • Building codes • Local covenants and

ordinances• Costs and benefits• Wind velocity and

frequency• Sizing • Certified products and

installers

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