The system will output the following:
Our analysis concluded that the average breakeven point for a given fire department installing solar panels on its trucks would range between 5 and 25 years depending on the amount of hours trucks idle. We also concluded that if the truck idles less than one hour per day (assuming trucks go out 75 days per year), the panel will not pay for itself during its lifespan (~25 years).
Solar for Fire Trucks Photovoltaic Panel Feasibility Model for Emergency Vehicles
Abstract:
The demand for diesel fuel has become a global problem that developed countries are seeking to mitigate any way they can. An increasingly common response is through investment in alternative, renewable energy such as solar power.When fire trucks go out on call and park on site, the plethora of electrical equipment on-board requires the engine to stay on, or idle, for the duration of the call. This wastes fuel and deteriorates the environment. US cities are looking for solutions to reduce their carbon footprint.We have designed a system that assesses the physical, economic, and environmental feasibility of attaching solar panels on the roofs of fire trucks (fire engines) for the purpose of saving fuel and reducing carbon emissions. This system is scalable and transferable to US cities. The system uses call times, fire truck specifications and geographic solar energy data to calculate how much fuel consumption and carbon emissions would be reduced by, and thence how much the city would save if it invested in solar panels for the fire trucks. The system performs an economic analysis of costs and savings (of installing panels) to calculate payback period, and ultimately a go/no-go decision (on investing) for the city's fire department.The goal of the project is to help the user decide on solar panel installation on fire trucks through a web-based interface.
Advisors:Dr. Andrew Huemmler
Dr. Jorge Santiago-Aviles
Demo Times:Thursday, April 19th, 2012
10:00AM, 10:30AM, 3:00PM, 3:30PM
TEAM #05Jorge Garcia SSE ‘12
Ramzi Ghannam SSE ’12Raymond Harari SSE ‘12
Modern fire trucks have a myriad of electrical equipment on-board that must be kept powered at all times. To sufficiently power this equipment, the engine must be kept running so the battery’s state of charge (SOC) does not reach a critical level, at which the battery can be permanently damaged. Thus, when trucks go out and park on site, they must idle for the duration of the call. This consumes fuel and emits carbon dioxide into the environment.
The past decade has witnessed the growth of an energy and environmentally conscious world. Cities around the world are looking to decrease their fuel consumption and carbon emissions through renewable energy. Philadelphia is one such city that is looking to reduce its carbon footprint and energy consumption. Greenworks, Philadelphia's initiative to become the greenest city in America, seeks to implement projects that could decrease its carbon footprint. A few fire departments throughout the country have experimented with installing solar photovoltaic panels on top of their trucks to reduce idle time. However feasibility varies by location due to differences in solar irradiance. Philadelphia’s Office of Sustainability contacted the University of Pennsylvania and expressed interest in exploring the feasibility of implementing this initiative.
We seek to evaluate the initiative of installing solar photovoltaic panels on the roof of fire trucks for the city of Philadelphia, and any other location in the US. We will achieve this by designing a model that:• Assesses the physical, economic and environmental feasibility of
installing solar panels on fire trucks taking into account:• Location-specific solar resource• Time of day and duration of call (fire truck goes out)• Truck specifications (battery and equipment )• Fuel costs• Panel Costs (purchase and installation cost)
• Provide a user-friendly interface.• Provide the user with the breakeven point, initial investment, fuel
savings, and CO2 emissions avoided.
Problem Statement
Proposed Solution
Project Objectives
Modeling the Sun - Location and time specific solar irradiance
The potential solar energy varies depending on location. We used the National Renewable Energy Laboratory statistics for average monthly irradiance in kWh/m2/day, and hourly date from major cities (source: Sharp Solar) to create a distribution of solar potential throughout the day for any location.
Building the System User Interface
Users, mainly Fleet Maintenance Supervisors, will choose their city, or input the average solar irradiance directly, the blocks of time during which they currently idle, and the number of panels they wish to install in a truck. Under advanced settings the user can modify technical inputs, which are defaulted to standard values we determined through research data. The model can be used for other types of vehicles by sufficiently adjusting the advanced settings.
Results
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25
-5000
-4000
-3000
-2000
-1000
0
1000
2000
3000
4000
5000
Cumulative Cash Flow
Years
Dol
lars
($)
System OverviewSolar Irradiance
Idle TimeCalculation of Energy generated by panel in
one day
-Truck Load-Battery
Specs
Solar Panel Specs
Installation not feasible: Battery will discharge too much
and get damaged
Does battery go below minimum
SOC?
Installation Feasible. Calculate fuel
savings.
Equi
pmen
t Sub
syst
emEc
onom
ic S
ubsy
stem
Economic Analysis Panel Costs
Suitable payback period?
Feasible
CO2 Emissions Avoided
Not Feasible
User inputs: Location and idling time blocks.
Determine if panels can power battery for previously stated time block considering electric load.
Calculate fuel savings, add researched costs.
Outputs: Breakeven point, initial investment, fuel savings, CO2 emission reductions.
System Flow
21000
)(*)(*)(/
mW
WHIrNPdayKWh
NP = Nominal power of Solar Panel (Watts)Ir = Solar irradiance of Location (kWh/m2/day)WH = Weighted hours per Day (Hours)
C
HICSOC V
Dis *)(min
C = Battery Capacity (Amp Hours)V = Voltage in system (Volts)Dis = Power Generated – Power Dissipated (Watts)HI= Hours Idling per Day (Hours)
Example Inputs Unit Days per year Days 75
Purchase cost Dollars 1300
Installation cost Dollars 3000
Interest rate Percent 10%
Hours/day Hours 2
0.5 1 1.5 2 2.5 3 3.50
5
10
15
20
25
30
Breakeven Point
Average idle hours per day
Year
s fo
r PV
payb
ack
Example Output Unit Initial Investment Dollars 4290
Breakeven Point Years 7
Yearly savings Dollars 1181
CO2 emission reductions Tons/year 13.23
AcknowledgementsThe success of this project would not have been possible without the continuous support of Philadelphia’s Office of Sustainability of the Mayor, Office of Fleet Management, and Penn Solar.
NO
NO
YES
YES