we need - soweb

Download We Need - SoWeb

Post on 12-Feb-2018




3 download

Embed Size (px)



Summary: This explains each formula used in the model to calculate your energy use (BEFORE page). Moving on to the NOW page there are up to 100 actions you can perform to reduce your energy use. The SUMMARY page displays the net impact of the reductions you pledge to performand some cool equivalent units of measurement. On the GROUPS page you can set up and join groups that aggregate (total) the net impact of all members. Soon a POPULATION page will calculate the total net impact of all users combined.

Key Information:

i. Save & Continue: You can save at any time and return where you left off.

ii. Info buttons: The info buttons have much of the information listed below.

iii. kWh/day Scale: All the formulas are set up to calculate your lifestyles resulting energy (kWh, kilo-watt-hour) use on a daily basis (see: What is a kWh? for a 1-pager). This way you can compare the energy cost of one flight per year to that of driving 10 miles per day, to that of eating out 2 times per week, to that of consuming a typical meat-eating diet at 3,000 calories per day.

iv. Key references: Sustainable Energy--without the hot air (free) is by David MacKay (chief scientific advisor, UK Dept. of Energy and Climate Change, DECC), and contains all the formulas used here (bare a few additions or adjustments). (The Quick Reference and Alphabetical Index to said free publication). All Conversion Factors used; and/or online calculators like Unit-Conversion. Another good source of information is the Carbon Trust.

v. Heating Degree Days Model: You can use this excel model to estimate your current heating/cooling (temperature data for about 300+ cities worldwide), and potential savings from changing the temperature on your thermostat. This could be helpful in the Heating and Cooling sections of this website, to construct your own estimated kWh cost per year.

vi. State of Earths Biosphere: This contains a short summary of some key scientific findings in this paper in Nature, Approaching Steady State Shift in Earths Biosphere









Here you can enter parameters that customize the model for your use.

Select either the METRIC SYSTEM or U.S. CUSTOMARY UNITS for the units of weight, length, distance and volume that you are most comfortable with, to calculate your energy (kWh). Note: You can switch between them at any time.

Everything is converted into kWh, i.e. kilowatt-hour, a universal unit of energy and always per day.

Why two different measurement systems? So an American using U.S. customary units, and a distant relative in South Africa using metric system units--can each calculate and aggregate (combine) their energy figures (in kWh per day)--and then effectively contribute their total energy-savings to people in need of reliable energy for food, health, and shelter.


Energy and Power? (David MacKay)

Systems of measurement (Wikipedia).

Energy Units, American Physics Society

Based on where you livewe can already calculate informed approximations for our energy-use.

Public energy-use estimates will load automatically. Things like data-centers, urban lighting, manufacturing and maintaining paved roads, fertilizer, transporting goods, government services, and military defenseall use energy. Each is approximated using World Bank data, and allocated evenly among the population (per capita).

Electricity generation source (i.e. how much of your electricity is generated using coal, hydro, natural gas, nuclear, oil, renewables) will assume you match your country electricity generation profile. Your sources may not match those of your country--soon you will be able to customize your sourcing. (This will show the CO2 reductions possible if your electricity were sourced using renewables v. fossil fuels).

City or Country Group Stats could be a cool way to compare each our contribution.


World Bank Search

CIA World Factbook

International Transport Forum - statistics

OECD iLibrary

Stockholm International Peace Research Institute

International Energy Agency

Did you know: 33 major U.S. businesses call for climate law (April 2013), and 61 companies and associations call for adopting a binding renewable energy target in the EU

What is my incoming water temp? Most water (in cities/industrialized places) is pumped via underground pipes, so the temp of incoming water is approx. equal to average groundwater temp.

Sources: For the U.S. this map by Eno Scientific has estimates for groundwater temps. Others will have to dig the web for your temps. A good estimate: Your groundwater temp is generally equal to the mean air temperature above land surface. Use the average daily temperature (annual) from 157 U.S. cities and 167 non-U.S. cities, updated by University of Dayton. Another source: National Climate Data Center.

Why is this temp important? It costs energy to heat water. Conversion Factors: 1 Btu is the amount of heat necessary to raise 1 pound of water by 1 degree Fahrenheit (F); the same way 1 calorie is the amount of heat necessary to raise 1 gram of water by 1 degree Celsius (C). Calculation: (useful temp, minus incoming temp) * water amount * conversion factor = energy unit cost.

Other References:

Gemstat: Global Environmental Monitoring System

Water temps in 4 select rivers/lakes in 20th C. in EU

Your water heater type affects your energy-use.

Right now you can select either an electric or gas water heater. You may have another type, like solar thermal or petroleum. These will be incorporated soon.

Regardless: 1 calorie is always the amount of heat necessary to raise 1 gram of water by 1 degree Celsius (C); and 1 Btu the amount to raise 1 pound of water by 1 degree Fahrenheit (F). Therefore the direct energy necessary to heat water is the same whether using electricity or gas. They differ in terms of efficiency, i.e. energy return on energy invested (EROEI), and carbon intensity, i.e. emission intensity, which makes one more or less energy intensive. We can determine our direct energy-use before determining and evaluating how we source that energy, and then ask, Can we live on renewables? (as David MacKay investigates), which should bring us back to energy-use.


Domestic water heating (David MacKay)

As Feynman put it, It is important to realize that in physics today, we have no knowledge what energy is. We do not have a picture that energy comes in little blobs of a definite amount.

Principle 1: Energy cannot be created, destroyed or recycled

High Efficiency Gas Boilers (from PexSupply)

We incur numerous costs using energy: land, natural resources, capital, energy to extract or transform, air pollution, greenhouse gas emissions, biodiversity, the health of ecosystems, and the biosphere.

And money. Note that: The final savings estimate this model calculates for youis an estimate. (By entering your price data here you agree to not suing anyone).


Check your electric, gas, or heating bill.

Electricity sales price data 2013 (EIA)

Natural gas prices (EIA)


Prices & Trends (U.S. Department of Energy (DOE)

Worldwide Retail Prices of Gasoline color map showing how expensive or cheap gasoline is across the globe.

Electricity generation source is assumed to match your country-wide electricity generation profile. If you know your electricity generation sources in % feel free to enter that. (If you changed it to 100% Renewables, you would emit far less CO2 in energy generation). Check out LCA of electricity generation technologies.

Why is this important? Because you can consume the same amount of energy and cost more or less pollution and/or emissions. This report, CO2 Emissions from Fuel Combustion (2011 Edition), from the International Energy Agency (IEA), on p. 39, has a table listing the average grams of CO2 emissions per kWh of electricity and heat produced in OECD countries from 2007 to 2009.

Calculation: kWh electric energy used, divided by %efficiency (EROEI), to derive total kWh chemical energy, and multiply this by the CO2 per kWh conversion factor.


Electricity Production (World Bank) from coal, hydro, natural gas, nuclear, oil sources.

U.S. State-specific figures will soon update automatically (for now they are available here).


CO2 Emissions from Fuel Combustion (2011 Edition)

LCA of electricity generation technologies

Changes to your water heater type and electricity source will soon be available. This is important because WATER HEATER TYPE and ELECTRICITY GENERATION SOURCE (technologies) impact CO2 emissions.

David MacKay determined in 2009 that the typical affluent person uses approx. 195 kWh/day, the average American, 250 kWh/day, and the average European >125 kWh/day (see: kWh/day/person by Country). How much you should use could depend on how equitably you want to engage the world. David MacKay determined that Europe does not have enough of its own renewables to provide 125 kWh/day/personit would need other countries' renewables. The world used 392 billion kWh/day in 2009, according to the International Energy Agency 2009 Energy Balance for World table. Thats approx. 60 kWh/day/person. We could set that as a benchmark: Stay within 60 kWh/day by either cutting down consumption and/or improving efficiency.

But we need to reduce GHG emissions by approx. 80-95%