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| Fig. 1: An example of the waste left behind from Hurricane Ike. (Source: Wikimedia Commons) |
Hurricanes are a powerful natural disaster that carry powerful winds and rain and leave behind destruction (Fig. 1) which can devastate communities and leave them to deal with the remains. In the United States and in many other countries, Waste-to-Energy plants are being created to deal help convert the destruction into usable energy. Countries such as China are rapidly expanding Waste-to-Energy plant capabilities. [1] Florida currently has 11 Waste to Energy (WTE) plants up and running. Florida and the northeastern region of the United States accounted for over 60% of the country's total waste to energy consumption in 2015 and the two regions continued to hold the majority in 2016, as well. The main purposes of these WTE plants are to reduce landfill reliance, utilize raw materials, create jobs, and to eliminate the pollution left behind causing the waste.
The Florida plants have a maximum capacity of converting roughly 20,000 tons of waste per day. Each county within the state has a differing trash pick-up plan in place, but the estimated tonnage produced by Hurricane Irma is greater than 2 million tons. The varying categories of waste are Refuse Derived Fuel, Municipal Solid Waste, and Industrial Waste (sludge, plastic scraps, etc.) This figure of 2 million is conservatively multiplied by a factor of .5 to convert it to dry mass (the only type of waste able to be used in WTEs). [2] The 1 million tons of dry mass contains a total energy EW given by
| EW | = | 1.0 × 106 tons × 0.91 tonnes ton-1 × 1000 kg tonne-1 × 2.1 × 107 joules kg-1 |
| = | 1.91 × 1016 Joules |
This is the amount of energy available should all the hurricane waste be used in WTE's. Florida hopes to deal with most of the waste by the end of the the 2017 calendar year by converting it into usable energy in WTEs, incinerating it, and relocating it to landfills. There will be a large portion of the waste created by Irma that will not be processed in these WTE plants.
Since a hurricane is powered by heat released by condensation into rain, the total mechanical energy dropped on Florida may be found by calculating the total amount of rain dropped upon Florida and multiplying this number by the heat of vaporization of water (2.257 × 106 J kg-1). We estimate the total amount of rain dropped on Florida to be about 6" (0.1524 m) distributed over the entire area of Florida (170,304 km2 = 1.703 × 1011 m2). The rainfall number was derived by considering the amount of rain dropped across the various counties in Florida where the range was from 2" to 16". The energy EH of the hurricane is then
| EH | = | 0.1524 m × 1.703 × 1011 m2 × 1000 kg m-3 × 2.257 × 106 Joules kg-1 |
| = | 5.86 × 1019 Joules |
Table 2.8 of the EIA's Elecric Power Annual says that Florida used 235,599 GWh of electricity in 2015. [3] Since 1 Wh = 1 Watt × 60 second/minute × 60 minutes = 3,600 Joules, the amount of electric energy EE that Florida used in 2015 was
| EE | = | 235,599 GWh × 109 Wh GWh-1 × 3.6 × 103 Joules Wh-1 |
| = | 8.48 × 1017 Joules |
The situation is summaarized in Table 1. By dividing the total energy in the hurricane waste by the total electricity used in Florida in approximately one year, we get 2.25%. Dividing the second two gives 69, meaning that the energy dumped by the Hurricane was nearly 69 times Florida's electricity for one year. The dumped energy was also 3068 times the energy contained in the debris created by the dumping.
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| Table 1: Summary of total energies in Florida. |
The combination of the waste created annually in the state coupled with the quickly-created million tons of waste created by hurricane Irma have the possibility of accounting for a large percentage of the state's energy production. The problem with all this waste is that Florida's current WTE facilities do not have the capacity to handle all of this waste. The waste that is cannot be converted in these plants is sent into landfills or burned.
© Keith Weisenberg. The author warrants that the work is the author's own and that Stanford University provided no input other than typesetting and referencing guidelines. The author grants permission to copy, distribute and display this work in unaltered form, with attribution to the author, for noncommercial purposes only. All other rights, including commercial rights, are reserved to the author.
[1] H. Zhou et al., "Classification of Municipal Solid Waste Components For Thermal Conversion in Waste-to-Energy Research," Fuel 145, 151 (2015).
[2] L. Lombardi, E. Carnevale, and A. Corti, "A Review of Technologies and Performances of Thermal Treatment Systems For Energy Recovery From Waste," Waste Manage. 37, 26 (2015)
[3] "Electric Power Annual 2015," U.S. Energy Information Administration, November 2016.
