Analyzing the Relationship Between Developed Lands, Solar Energy, and Public Transportation

Needs in MinnesotaAlex Plunkett and Tommy Schlundt

Outline

• Solar advantages• Electric bus system• Current bus infrastructure in Twin Cities• Research question• Methods• Land requirements• On the small scale

Why choose electric?

• Electric energy from solar allows the gain of energy without putting carbon into the atmosphere.• Solar is statistically reliable. • Solar technology is quickly advancing and is becoming more viable

than ever. • Could be the answer towards Minnesota's development as a

renewable energy sustained state.• As electricity becomes more valuable and expensive to produce, solar

panels become much more valuable becomes after upfront costs, the electricity is essentially free.

August 26, 2009•DOI: 10.1371/journal.pone.0006802

• http://static.newclimateeconomy.report/wp-content/uploads/2014/08/NCE_Chapter4_Energy.pdf

The cost of Photo-Voltaic Cells are at an all time low, and are only becoming cheaper and more efficient.

The company Sun Power has a new line of PV cells called the E-Series that have a record breaking 20.4% efficiency.

Viability of Photo-Voltaic Power

The BYD Electric Bus-The newly designed BYD electric transit bus uses a non toxic and environmentally friendly Iron-Phosphate battery alternative to traditional toxic Lithium-Ion batteries.

-Many electric vehicles currently use the lithium-ion design such as the tesla and chevy volt

-and they pose environmental problems when it comes time to replace the batteries.

-Also, when charged these batteries can produce lots of heat which could cause some serious fire and explosion hazards.

-while the iron-phosphate batteries do not heat up as much greatly minimizing the potential risk

-A single charge can provide up to 155 miles worth of transport at 1.92Kwh per mile. Suitable for the majority of public transit needs.

Minnesota Busses

• On average every twelve years Metro Transit replaces their busses after driving approximately 400,000 miles due to conditioning and usual wear and tear• This means that Roughly 33,333 miles are traveled by each bus per

year• The Metro transit fleet contains 905 busses • Equating to 30,166,365 miles total miles annually

What are the land requirements for powering Minnesota’s buses using solar power?

How much power can panels provide?• A square kilometer of cells would optimally provide 4.6 gigawatt

hours of energy a day. Factoring in 20.4% efficiency of the panels yields 0.9384 gigawatt hours of energy a day. • In one year, this solar array would provide 342.516 gigawatt hours of

energy. • Only a fraction of this would be needed to power BYD busses

Land Requirements for Minnesota Busses• BYD busses using 1.92KwH per mile at 30,166,365 miles traveled

annually would require 58 GwH of power a year.• This is 17% of the power a 1 square kilometer solar array would

produce • Only 170,000 square meters would be required to sustain all fixed

route public busses in a year.

Where can the Solar Panels be Placed?• Utilizing degraded urban lands such as paved areas for the most

efficient areas of placement. • Utilizing GIS mapping with the impervious layer from the national

landcover database, we were able to find exactly where these areas exist in the metro.• 190 green squares needed

Small scale feasibility

• Using the made in Minnesota rebate program, we were able to predict the amount of solar energy the solar panels on top of Anderson student center would make• University of St. Thomas’ current panels produce approximately

56,688 KwH a year• If St. Thomas replaced their current transit bus with a BYD electric bus

it could travel 29,525 miles a year.

Future Research

• Transitioning towards uses in the light rail, Amtrak, Also could lead to law enforcement and ambulatory services• Vehicle-to-grid is a concept where you allow the electric vehicle to

charge when the cost of electricity is low, such as during the day. Although, during the night, the cost of electricity significantly goes up, causing the vehicle to stop charging. • Utilizing solar to power personal electric transport• Moving away from polluting recreation vehicles such by replacing 2-

stroke motors with electric drive trains.

In Summary

• Solar Energy is becoming greatly viable• Electric Vehicles are becoming safer and more efficient with

advancements in battery technology• 170,000 square meters of solar panels needed to replace current bus

transit systems with electric systems• Making use of paved and degraded lands would be optimal as they

are close and around to where the bus transit system is.

Bibliography

• http://static.newclimateeconomy.report/wp-content/uploads/2014/08/NCE_Chapter4_Energy.pdf - declining cost of PV cells

• http://us.sunpower.com/ - E-20 Panel Information

• http://www.metrotransit.org/ - Twin Cities Bus Information

• http://www.byd.com/na/auto/ElectricBus.html - Electric Bus Information

• www.ci.minneapolis.mn.us – summary picture