Solar Energy Opportunities for New Schools July 10, School Board Work Session

Transcription

1 Solar Energy Opportunities for New Schools July 10, 2017 School Board Work Session

2 Not a New Concept 1865 Solar energy used to power a small steam engine (solar thermal power) Discovery that when selenium was exposed to light, it produced electricity. Proved that light without heat or moving parts can be converted to electricity First solar power company formed (The Solar Motor Co.) 1953 The silicon solar cell developed, first used in toys and radios.

3 What is Solar Energy? Photovoltaic (PV) cell is a direct current generator powered by light. Energy of light is transmitted by photons, small quantums of light. Electrical energy is stored in electromagnetic fields, which in turn can make a current of electrons flow. Solar cell coverts light, a flow of photons, to electric current, a flow of electrons. Light photons strike the PV cell, knocking electrons free in the silicon crystal pushing them through a circuit, and returning them to the other side of the PV cell.

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6 Solar Energy at Schools Prior to 2008 there were less than 750 schools in the US with solar installations over 3,000 schools added solar installations in the US. 2.7 million students attend a school with a solar installation. These installations provide over 642,000 MWh or electricity per year. Equivalent to power over 60,000 homes.

7 Solar Energy at Schools

8 School Solar Installations

9 Average PV System Size by School Population

10 Solar Financing at K 12 Schools

11 School PV System Size Distribution by Number of Systems

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19 Solar Energy Options for Schools Education A very small, typically 1 KW, installation at a school for educational purpose. Net Zero The solar energy system provides the same amount of electricity the school consumes. Energy Positive The solar energy system provides more energy than the school consumes. Net Metering A smaller solar system installation that serves the school and excess is sold to the grid.

20 Calculating Solar Needs at School Based on Energy Use Intensity (EUI) of the school Calculated by dividing total energy consumed in one year by size of building. EUI = ((annual kwh x 3.412)+(annual therms x 100))/ building square feet = kwh/sf/year The lower the energy used by a school is, the lower the EUI will be Based on EUI goal of 28, New Area I ES will require: 700 KW solar energy system to be Net Zero 750 KW is maximum area to be energy positive Area has 1,400 full sun hours per year Current $ per KWh

21 Cost to Install Solar Energy at School Cost to install the solar energy: 700 KW solar system to be Net Zero: $2,100,000 At current rate for electricity the return on the investment is over 27 years. Panels degrade in their ability to convert light to electricity at a rate of 0.5% per year, or 15% by year KW is maximum area to be energy positive: $2,250,000 At current rate for electricity the return on the investment is over 30 years. 200 KW Net Metering system: $600,000 At current rate for electricity the return on the investment is 20 years

22 Average Commercial Electric Rates Average Commercial Rates for North Carolina Year Cents per KWh

23 Challenges for Solar Energy at Schools Education Can be provided through grants, programs with local electric utility, low upfront cost. Will not provide power to offset school consumption. Net Zero and Energy Positive Programs available to private sector to provide solar energy systems through tax credits, schools unable to take advantage of credits and must pay 100% cost. Electric utility buys renewable energy at half the cost for what they sell energy for. Panel efficiency degradation, utility company buy rate and ROI will not allow benefit of cost savings Do it because you want to.

24 Challenges for Solar Energy at Schools Net Metering Programs available to private sector to provide solar energy systems through tax credits, schools unable to take advantage of credits and must pay 100% cost. Electric utility buys renewable energy at half the cost for what they sell energy for. Panel efficiency degradation, utility company buy rate and ROI will allow benefit of cost savings after 20 years. Can include on the new elementary school. Can provide a smaller KW system on the ACC, up to approximately 150 KW.

25 Education Missouri Department of Economic Development, Division of Energy Goal to bring solar power and education to K 12 schools Provided a 1 KW solar array post mounted and education program Educate the students, teachers and community about the importance of electricity as an energy form and the value of renewable energy

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29 Recent Effort to Use Solar Energy at Durham Public Schools Student led initiative Ask DPS to adopt a goal of 100% renewable energy Barriers in place that prevent achieving the goal Structure in place currently incentivizes private sector investment in solar by tax benefits Cost of system exceeds utility buy rate for power

30 Staff Recommendation for Solar Energy at New Schools Engage the design teams to develop an alternate to install a 200 KW net metering system on the roofs of new elementary schools and up to 150 KW net metering system on the ACC. Once the bids for school construction are received, present the alternate bid price for solar energy system installation along with a life cycle analysis to the Board for consideration.

31 Solar Energy Opportunities for New Schools July 10, 2017 School Board Work Session