PV Research Summer 2016

Summer 2016: Direct consumption of DC electricity from PV solar panels. Summary of Summer Research
See what we will be doing in Summer 2017
Please read a story about us in the Cal Poly News.

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Meeting at the Student Experimental Farm to eat chili cooked in our PV cookstove
Back, left to right: Maxwell (Xem) Muscarella, Tom Headland, Mike Stromecki, Pete Schwartz, Brian Aunger, Omar Arriaga, Brent Taylor, Tyler Watkins, Ryan Perry, Pablo Arroyo, Ryan Wang; Front: Adeel Ali, Ryan Lau, Wilson Yeh; Missing: Diana Swanson, Garrett O’Neill, John D’Ambrosio, Maddi Flemming, Chris O’Day, Ian Stone, Nathan Heston, Tod DuBois.

Summary of Activity
Solar-Electric panels have steadily decreased in price since 1970, dropping to 1/2 the cost each 5 years on average; and drastically increased in deployment rate (see graphs below). At present, the cost of solar panels represents only about 20% of the cost of solar electricity, with the rest being the related electronic hardware, installation and the permitting and paperwork in connecting to the grid. We look ahead, asking the question, “when solar electricity is free, how will it change the way we use electricity?” Scientific American Agrees, and is also seeking to answer these questions. We look at it here in the industrialized world and in poor countries, where cheap solar electricity is already and will continue to transform growth. We are investigating novel deployment of PV solar panels that use the DC electricity directly rather than connecting to the AC utility grid. The benefit of this includes:
1) Reduction in electrical conversion losses from DC to AC and back to DC again. Most devices run on DC electricity and so must rectify the AC grid electricity.
2) Reduction in installation costs: Solar panels have become increasingly inexpensive and presently constitute only 20% of cost of a grid-tied PV system. Much of the cost is the labor to install the panels, as well as the contracts and hardware related to grid connection. By not connecting to the grid we can reduce the cost of PV electricity by 50% or more. Additionally, new legislation in Arizona and Nevada has increased the cost of connecting to the grid to be prohibitively expensive.
3) Reduction in barrier to go solar. By allowing people to add PV piecemeal, there is little barrier to try solar.
4) Creating awareness of electricity use and the subsequent load shifting toward demand side management. When people realize that they get free electricity during daylight hours, they will be inclined to use this electricity more prolifically. This awareness will likely support a cultural shift that will facilitate inclusion of intermittent electricity generation and thus promote sustainable electricity use.

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On Average, the cost of solar cell production has been cut in half every 5 years. Present cost is well below $1 per Watt.

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Left (http://blog.ucsusa.org/john-rogers/installing-solar-panels-on-your-roof-692), the price of solar panels (blue line) has decreased and presently constitutes only 20% of the cost of installing solar panels with the rest of the cost being installation and the hardware and permitting associated with connecting to the grid. Right, the California load curve illustrates the demand on conventional electrical generation facilities throughout the day. The largest demand used to be about midday with another small spike in the early evening when people return home. The increasing contribution of solar electricity drastically reduces demand in the day, presenting the utilities with significant challenge in ramping up generation to meet evening demand.

The above graph from Green Tech Media illustrates the rather linear growth in the rate of PV deployment, indicating a quadratic growth in the capacity of solar electricity generation.

Photovoltaic Cookstove – Low cost, high efficiency cooking for the poor. Please see 5-minute video and publication.
Electrical Priority Switchboard – Using locally-generated electricity directly onsite.
Photovoltaic DC Water Heating – Residential water heating for Grange Hall in San Luis Obispo,
Electric Bug Vacuum – Building a Bug Sucker for organic pest control.
Direct DC-DC EV charging – Electric Vehicle Charging for Grange Hall in San Luis Obispo,
Solar Energy Conversion Methods – Finding the most efficient and cost-effective converters
Computer Control and Data Loggers – Controlling and documenting flows of electrical energy
Solar Ice – Producing ice with solar electricity
Solar Powered Mushroom Production, and Other Agricultural Processes

We are investigating several ways to implement PV solar panels directly. We have two collaborations:
1) At the Grange Hall in San Luis Obispo, we are planning to deploy PV solar panels (a donation from SunPower through Cal Poly) for direct DC consumption of electricity. This will be an ongoing collaboration as we explore more ways to displace utility AC electricity. Another collaborator is Sangha Energy, where students will gain practical experience.
2) In Uganda, we are working with AidAfrica to deploy Solar Powered Cooking Capability. This summer, four students will spend a month in Uganda with AidAfrica to study how people cook there and deploy a few Solar Ovens. Jared Becker, graduate student from University of Iowa, is interested in joining us on this solar cooking work and may visit this summer.
3) With Ashraf Tubeileh (Cal Poly Horticulture and Crops Science), Mike Stromecki, we are designing solar electric bug-suckers for pest control in organic agriculture. We will look at replacing AC motors with DC motors in refrigerators and air conditioning systems.
4) With Nathan Whitman and Ashraf Tubeileh, we are introducing PV sterilization for mushroom cultivation.
5) We will look at replacing AC motors with DC motors in refrigerators and air conditioning systems. This project may have lots in common with the bug-sucker project. We will consider options for microinverters or power optimizers instead of turning AC motors into DC motors.
6) With Nathan Heston (Cal Poly Physics), we are developing ice making capability for developing countries.
7) Working with George of digdeep.org, we will design an PV electrical system to pump water from wells on Navajo Nation land. Matthew Graham, graduate student is interested in Grey water and may possibly work with the desalination project below.
8) Working with Rebecca Oulton (Cal Poly Civil Engineering) and graduate students Nick Skouras, we will investigate inexpensive options of solar thermal desalination.

Research Redesign Ideas for 2017