| Over the past several years we have all become | | | | grow and process the crops. So we will take |
| painfully aware that CO2 emissions from fossil | | | | every acre of plantable land on earth and plant |
| fuels likely play a significant role in worldwide | | | | the most efficient crops we know of to generate |
| climate change. Our insatiable demand for energy | | | | biofuels. That should do it. Well, not really. That is |
| is driving prices up and generating more CO2 than | | | | only about 3 Terawatts. But we are on a roll, so |
| ever. | | | | let's continue. |
| How Much We Use | | | | Solar Cells |
| Today, the world uses about 12 Terawatts per | | | | Photovoltaic technology has come a long way in |
| year for all uses. That is 12,000,000,000,000 | | | | the last few decades. Efficiencies have improved |
| Watts. In a separate article I reviewed these | | | | and costs have come down. And more plants are |
| sources of use which break down as: | | | | being built to supply more solar. A good size solar |
| Built Environment = 52% (40% for operations | | | | plant today can manufacture enough solar cell's to |
| and 12% for materials) | | | | generate 1 gigawatt annually. Of course it would |
| Industry = 24% | | | | take 1000 plant-years to get to 1 Terawatt. And |
| Other Transport = 15% | | | | a lot of silicon (or other substrate). If we can |
| Passenger cars = 9% | | | | make 20,000 square miles worth of cells and |
| Energy from Many Sources | | | | place them in sunny areas on earth, it will take all |
| There has been a lot of conversation about | | | | of the output of the current and planned plants |
| renewable energy sources such as solar, wind and | | | | for the next 25-30 years. And how much power |
| others. One would think we are now generating | | | | is that? About 2 Terawatts, if all goes right. Of |
| 30% of our overall needs from these sources. | | | | course, only during the day, but that is another |
| Unfortunately, that is not the case. If we break | | | | issue. |
| down the sources of energy worldwide we get: | | | | Add It All Up |
| Oil = 35% | | | | Adding up the largest sources at levels that we |
| Coal = 27% | | | | likely cannot attain, we still only end up with 6 |
| Natural Gas = 20% | | | | Terawatts out of the 30 Terawatts total required |
| Hydro = 6% | | | | to meet our needs. Add in wind, solarthermal, |
| Biomass = 6% | | | | wave energy etc. and there is maybe another |
| Nuclear = 5% | | | | Terawatt. So basically, while these are all excellent |
| GeoThermal = under 1% | | | | businesses and fine technologies that must be |
| Wind, PV, SolarThermal = under 1% | | | | pursued, we cannot count on renewable energy |
| The largest energy sources are Oil, Coal and | | | | sources alone to get us to the promised land. |
| Natural Gas. All fossil fuels which generate | | | | Conservation |
| significant CO2 emissions. And the cost of all of | | | | The only hope we have of addressing CO2 and |
| these fuels has doubled in from 2007 to 2008. | | | | climate change is conservation. Since renewables |
| Future Energy Demand | | | | can only deliver some 6 to 9 Terawatts total, we |
| Our demand for energy is increasing worldwide, at | | | | have to deal with as much of the 21+ Terawatts |
| an ever increasing rate. Given the current rate of | | | | in other ways. As discussed earlier, the built |
| increase, several estimates put worldwide demand | | | | environment is responsible for 52% of worldwide |
| at 30 Terawatts within 30 years, an increase of | | | | CO2. In order to address the built environment, |
| 18 terawatts, more than double today's | | | | we need to address the materials (such as new |
| requirements. So we need move to renewable | | | | cement, drywall, metal processes) as well as |
| sources which don't generate CO2 when burned. | | | | building operations (primarily heating and cooling). |
| Solar, biofuels, nuclear. Sounds like a plan! Or is | | | | Companies like CalStar and Serious Materials are |
| there trouble in paradise. Let's consider each one. | | | | re-inventing the old processes, reducing embodied |
| Nuclear | | | | energy by 75% or more. |
| Nuclear power generation does not emit CO2, or | | | | We all can address operations, at least at home. |
| much of anything else. The heat from a controlled | | | | Easiest targets are sealing ductwork, installing |
| nuclear reaction boils water into steam that spins | | | | programmable thermostats, insulating homes that |
| a turbine. 3 new plants are planned and beginning | | | | aren't, and choosing high R value windows (at |
| the license process in the US. And possibly as | | | | least R6 and preferable higher). Up to 50% of |
| many as 8 worldwide this year (requesting | | | | heat loss occurs through windows which are |
| licenses). Let's go out on a limb and hope that | | | | closed. Upgrading to dual pane low E windows is |
| somehow that figure grows to 45 new licenses | | | | only gets to an R3. New technology is becoming |
| this year, and 45 more every year for the next | | | | available (such as ThermaProof Windows) which |
| 30. And they each take no more than 10 years | | | | can provide R values above R10. A 300% |
| to build. And what is the result of in 30 years? 1 | | | | improvement and a significant savings in heating |
| Terawatt. Not the 30 total we need, or the 18 | | | | and cooling bills. |
| additional Terawatts in growth. Just 1 lousy | | | | The Result |
| Terawatt. Puts it all in perspective. | | | | If we begin addressing out built environment, we |
| BioFuels | | | | can easily reduce the energy required by 75% |
| This technology is controversial since it takes real | | | | over today's inefficient buildings and materials. The |
| energy to grow and harvest crops. The full | | | | result would be a 12 terawatt savings in 30 years. |
| analysis of many of the biofuel processes we | | | | And it is the least expensive 12 terawatts |
| have suggests that some (such as corn ethanol) | | | | available, much less expensive than more coal |
| use more energy to make and distribute than we | | | | power plants, which is the alternative. |
| get back out. But that argument aside, let's | | | | So what will you do? Save the environment and |
| pretend for the moment that we get 100% | | | | your energy bill too. Make the right choice and act |
| efficiency and there is no energy required to | | | | now. |