VISUAL
SPOKEN
RENEWABLE ENERGY
AND THE FEASIBILITY OF GENERATING
ELECTRIC AND
THERMAL POWER
FROM
WASTEWATER
Council members, mayor Jenks and Mr. Butz:
Thank you for this opportunity to address you on renewable energy and the feasibility of generating electric and thermal power from wastewater.
The continued emissions of greenhouse gases, particularly carbon dioxide, place the Earth at risk of increased severe weather events such as hurricanes, floods, and droughts. These severe weather events engender losses: crop failures, wildfires, and resource wars. For this reason the world has experienced a tremendous growth in renewable energy.
These graphs show the yearly change in atmospheric carbon dioxide, the major greenhouse gas, and average global temperature at the Earth’s surface.
Both carbon dioxide concentrations and average surface temperatures are rising.
Here we superimpose the two previous graphs. We see that carbon dioxide concentration lies very close to a smoothing of the average global surface temperature.
Here we note that weather related disasters have more than doubled over the past 20 years and the ten warmest years on record since 1880 have all occurred within the past 12 years.
Political and industry leaders are finally getting the message that the health of the Earth and human communities depends on confronting this crisis through energy conservation and development of non-polluting renewable energy sources. These graphs show tremendous growth in wind and solar power.
Costs of NEW generating capacity
(Busbar, Cents per KWh)
May 2008 California Energy Commission
| Biogas | 8.6 |
| Wind | 8.9 |
| Gas (CC) | 9.4 |
| Geothermal | 10.2 |
| Hydroelectric | 10.5 |
| Coal (SC) | 10.6 |
| Coal (IG) (CC) | 11.5 |
| Solar Thermal | 12.7 |
| Nuclear | 15.3 |
| Biomass | 16.5 |
| Coal (IG CC CCS) | 17.3 |
Busbar includes capital, fuel & operating costs
CC - Combined Cycle
SC - Supercritical
IG - Integrated Gasification
CCS - Carbon Capture & Storage
This 2008 study by the California Energy Commission shows the cost of new electricity generating capacity. Biogas, a non-polluting renewable energy source, leads the pack at 8.6 cents per KWh. Wind is a close second at 8.9 cents.
The cost of solar energy is high, but has come down considerably since this study was done. Costs may drop precipitously as the new thin-film solar technology is developed.
This flow chart shows how biogas electric generation works. Organic matter decays in an anaerobic digester creating methane gas which is a greenhouse gas 25 times more powerful than carbon dioxide. The methane is oxidized creating electric power and heat, which are necessary to the function of modern wastewater treatment plants.
Biogas generation actually reduces emissions of greenhouse gas and will provide considerable carbon offsets in most proposed systems of carbon taxes and credits.
Soon we are likely to have to pay a carbon tax or buy carbon permits which may increase the cost of coal generated electricity by 35%.
Biogas technologies are flexible, providing a wide range of sizing options.
As of
September 2007
there were
79 wastewater treatment plants
in 24 states from
New York City
to
Portland, Oregon
with combined heat and power (CHP)
biogas generation systems
for a total capacity of
223 MW.
As of September 2007, there were 79 wastewater treatment plants in 24 states with combined heat and power (CHP) biogas generation for a total capacity of 223 MW. The use of biogas generation at municipal wastewater plants is increasing.
Albert Lea, Minnesota
Demographics
Albert Lea Wastewater Treatment Facility
Cost
Payback
Benefits
I will focus on Albert Lea, Minnesota because its demographics are so similar to Rolla’s.
Albert Lea is a regional center and a rural community of 18,000 people
Its Wastewater Treatment Facility uses an anaerobic digester
and four 30KW microturbines for the generation of heat and power.
The cost to Albert Lea was $76,000 with the remainder of this ¼ million dollar project coming from state and industry grants.
Albert Lea will recoup its costs in under 2 years.
Benefits are:
Annual energy savings of 40 to 60 thousand dollars.
Reliable, low maintenance, 24/7 generation of 800,000 kWH/yr and 28 M Btus of recoverable heat, and
Environmentally friendly reduction of greenhouse gas generation.
Rolla's main wastewater treatment plant
is a Good Candidate for
Biogas energy generation.
If the answer to two or more of these questions is “Yes” then we can benefit from CHP biogas generation.
1. Do we have an influent flow rate greater than 5 million gallons per day?
2. Do we pay more than $0.06/kWh for electricity?
3. Is reliable, high-quality power and thermal energy important to us?
4. Is it important to reduce energy costs and increase the overall energy efficiency of our wastewater treatment process?
5. Do we want to increase your facility’s environmental performance?
Is Rolla's wastewater treatment plant a Good Candidate for Biogas energy generation?
Our inflow rate is somewhat less than 5 million gallons per day but:
We pay more than $0.06/kWh for electricity?
Reliable, high-quality power and thermal energy is important to us.
It is important to reduce energy costs and increase the overall energy efficiency of our wastewater treatment process.
It is important to increase our environmental performance.
So Rolla is an excellent candidate for CHP biogas generation.
THINK GREEN
All that is required is the will.
In any decision we make, we must always consider environmentally friendly options
In conclusion: THINK GREEN
Always consider environmentally friendly options. They are often the most cost-effective. Just compare the advantages of biogas generation to our high cost, high maintenance diesel powered backup generators and our heavy investment in coal-fired electricity.
We can turn our wastewater into electric power.
We can also turn our municipal yard and kitchen wastes into electric power.
We can generate electricity from wind and solar energy.
We can retrofit our buildings for energy efficiency.
We can turn Rolla and RMU into a showcase of environmental efficiency.
All that is required is the will.