4. Energy Efficiency and Conservation and the Renewable Electron Economy
(originally published October 19, 2008)
In the first three parts of this series for policymakers I have reviewed how we can fairly rapidly transfer our transport energy demand from exhaustible fossil fuels to renewably generated electricity, how that electricity can be generated, and what policy instruments are available to help build the Renewable Electron Economy. We have determined that this undertaking will require substantial investment and increased overall expenditure for energy and transport yet will be not nearly as expensive as continuation of the status quo. However, a key factor in achieving the most ambitious climate protection and energy independence goals, is the rapid implementation of energy saving techniques and technologies, which are facilitated by the use of a selection of key devices, most of which are driven by electricity.
Energy Conservation and Energy Efficiency
Most analysts acknowledge that the least expensive and most rapid route to meet the first several “tranches” of our carbon emissions reduction and energy independence goals is by avoiding having to generate as much electricity or drill for as much fossil fuel for transportation in the first place. Energy efficiency (EE) and energy conservation are different but related concepts, though they are often confused. Energy efficiency means that users of powered devices can get the same enjoyment or use out of a more efficient device that uses less energy. Energy conservation is a planful pattern of human action by which energy use is avoided. Energy efficiency and energy conservation can be more or less linked together. As a concrete day-to-day measure, energy efficiency is considered to be more effective than energy conservation because once a device is installed, it takes the choice to waste energy out of the hands of people, while conservation requires human effort and choice. On the other hand, the value of energy efficiency is enhanced and its implementation facilitated by an pre-existing ethic of energy conservation that may permeate a society as a whole; investors and governments are more likely to prioritize energy efficiency investments if they believe that resources are valuable, limited and ought to be conserved.
The importance of an ethic of conservation in promoting both energy efficiency and renewable energy has been underplayed in part because of the political defeat of Jimmy Carter in 1980, who was the most powerful public figure in recent memory to actively promote energy efficiency and resource conservation. Historian and political commentator Andrew Bacevich has contrasted unpopularity of Carter’s image as a prudent conservator of resources versus the then more attractive image of the swashbuckling Ronald Reagan who painted the picture of an America of infinite resources and prosperity. Bacevich sees Reagan as the “prophet of profligacy” an attitude, because of Reagan’s political influence to this day, that has colored the American view of the ethic of conservation. At the moment we seem to be at a turning point against this decades long stereotyping of the pursuit of conservation, where green is fashionable and oil companies are declaring in expensive TV commercials that conservation is an imperative.
While on a national level, support for energy efficiency has been inconsistent, California’s state government has since the initial oil shocks of the 1970’s developed a set of energy efficiency regulations of utilities and building standards that remain the state of the art within the US. California’s energy use per capita has remained steady since the 1970’s due to a successful energy regulatory environment and despite rising population in hotter areas of the state away from the temperate coast. Some of the early, fairly easy national measures for energy efficiency can be achieved by adopting wholesale or revised versions of California’s regulatory culture.
Energy Efficiency: Generating “Negawatts”
The energy guru Amory Lovins coined the term “negawatts” to describe how gains in energy efficiency can avoid the production of large quantities of energy, meaning “avoided megawatts”. Lovins likes to call energy efficiency and negawatts “the free lunch that you’re paid to eat”. Highly influential, Lovins is relentlessly up-beat about how energy efficiency is a sound business and product design practice, though his enthusiasm downplays the challenges facing energy efficiency in the American context where energy is still relatively cheap. While in Europe and Japan, the higher cost of energy facilitates investment in energy efficiency without incentives, in the US, systems of incentives have been necessary, most notably successful in California, to encourage significant adoption of energy efficiency measures.
One can compare the price of negawatts to megawatts as a decision-making tool. A modern power natural gas power plant can cost somewhere around $2500/kilowatt of power to build. The cost of power from this plant can, in addition, rise as the price of the fuel (inevitably) goes up. On the other hand, an efficient lighting project, especially where there is a substantial leap downward in wattage between old and new fixtures, can cost around $1000/kilowatt, fuel “included”, which will in effect becomes cheaper as the price of power rises (or conversely, the return on investment will accelerate). Not all energy efficiency projects are as inexpensive but the same principle applies that as the price of power goes up, the return on investment on an installed energy efficiency project gets more favorable.
If energy efficiency and new clean generation are not played off as an “either/or” proposition, the extra expense of new clean generation will spur energy efficiency investment, as the higher per kilowatt-hour costs of a new technology will make investment in energy efficiency all the more attractive. More efficient use of energy will in turn lower the overall costs of building a new clean infrastructure as less generation capacity will need to be built. The interplay between new clean generation and energy efficiency then will function as a “virtuous circle”.
Utility Revenue Decoupling and Energy Efficiency
In 1982, to align the interests of the investor-owned utilities with the State of California’s goal to increase energy efficiency, the California Public Utilities Commission created an innovative system by which utilities would not suffer decreases in revenue by reducing power sales. The decoupling of utility revenues mandated that utilities invest a certain amount in energy efficiency programs, usually through rebates for energy efficient devices and device installation, yet allowed the utilities to recover lost revenues from these reductions in power sales by increases in power rates the subsequent years. These increases, in turn, facilitated further investments in energy efficiency as higher power costs spurred power end users to put more money into more efficient end-use devices. California has higher power costs than surrounding states but power use has remained around 7500 kWh per year per person since 1977 as power use has risen throughout the United States to an average of 12,000 kWh per year.
Utilities under decoupling regulation have found that investment in energy efficiency is a way for them to avoid or postpone large scale capital investments in new power contracts or transmission and distribution infrastructure. Northern California’s large investor owned utility PG&E for instance has invested three times as much in energy efficiency as is mandated by the state for just these reasons. In addition, investment in energy efficiency is good public relations in an era in which being green is considered a public virtue.
Recent policy proposals including that of the Barack Obama campaign to increase energy efficiency throughout the US suggest making revenue decoupling a national requirement for all utility regulatory structures.
Green Design: Guiding Natural Energy Flows
Energy supply in a renewable electron economy means tapping into natural energy flows or gradients and using them to generate electricity to power useful devices. But what if those currents of natural energy and material flow had desirable uses in their stronger, unconverted natural forms? As we have already established, renewable generators are, at least with current technology, not inexpensive and like most electric generators, convert only a fraction (from 10 to 40%) of the primary energy they receive into electricity.
One way to think of green design and building principles is that they are able to route natural energy flows to serve a desired human end, avoiding the losses and expense associated with converting the energy into a new form, like electricity. For instance the heat from sunlight or from the bodily warmth of people and animals can be used to keep the interior of buildings warm during the winter with the proper materials and construction. Or natural light can be used to light the interior of buildings through windows and skylights or through new fiber-optic daylighting systems and solar tubes. Wind can be used to cool a building through wind towers in hot dry climates. An awareness of these natural flows and gradients is one of the most important tools of the green architect or designer.
Advanced materials also allow green buildings to work against natural energy flows if so intended by the building’s designers or occupants to keep a space warm or cold, dark or light. Superinsulation and advanced window technologies allow buildings to use almost no energy to maintain comfortable interior temperatures with minimal heating or cooling energy required. Older technologies like straw-bale design and adobe walls can have a similar effect in declaring our intention to keep a space warm or cool, fighting against the entropic tendency for heat and moisture to evenly disperse across natural barriers. Pre-fabricated building and building parts allow for more precise design tolerances and tighter buildings as factory construction is more precise than what can occur on site.
Near-zero, Net-Zero and Plus-Energy Buildings
While green building encompasses more than a focus on energy usage, reducing the energy use and attributable greenhouse gas emissions of buildings is one of the key concerns of green builders today, contributing for instance approximately one-third of the potential points to the LEED green building rating systems. Near zero energy buildings are achieved with the application of efficient building technologies, green building principles and some on-site renewable energy generators, most often solar PV panels. However, a near-zero energy residential building can also be achieved exclusively through the application of hyperefficient building technologies without on-site renewable energy capture and generation.
One building system that can produce near zero energy buildings are “passive” buildings or houses that use ambient energy from the sun to be heated in the winter and cool from the upper layers of the ground to remain cool in the summer. Passive houses or buildings are super-insulated and use an air-to-air heat exchanger (driven by small electric motors) to preheat or pre-cool incoming air with exhaust air thereby keeping interior air fresh while preserving the desired interior temperature. A passive house can use 15% of the energy of a non-passive house for space-conditioning; furthermore, the heat given off by lighting can contribute significantly to the warmth of the house in the winter leading to a two-for-one effect.
Building closer to the ground or using thick earthen or naturally insulated walls can in almost all climates reduce the need for space conditioning, as the temperature of the ground and groundwater remains fairly constant relative to the air temperature. Also the introduction of walls or floors as thermal masses gives architects another tool to reduce building energy usage by storing heat or “cool” in these masses for slow release later on. The “Earthships” by New Mexico architect Mike Reynolds, use the thermal mass of thick walls and thoughtful design in relationship to their environment to reduce or eliminate the need for space conditioning. A new technology, borehole thermal energy storage or BTES, is a means to use installations of thermal masses in the ground to store the heat of the sun during the summer which remarkably 6 to 9 months later is still available during the winter to heat buildings and other processes.
To push beyond near-zero energy threshold, net-zero and plus-energy buildings require the application, sometimes liberally, of PV or wind turbine technologies to cover the internal uses of energy in the building, even as the buildings exchanges energy with the local utility via the grid. The mix of building efficiency vs. on-site power generation technologies will be influenced by the relative cost of these technologies, the uses of the building (residential, office, industrial), the local climate, the intentions and commitments of the builders and owners, and renewable energy resources available. It may be more inexpensive at one point in time or place to apply efficient building technologies but at a point of diminishing returns, the purchase of PV panels or an on-site wind turbine may become the most feasible option. With more power usage per square foot, to achieve net zero or plus-energy, requires of necessity more on-site generation. Compared to the building techniques of the last couple centuries that depend on energy subsidy from coal, gas, oil or wood for comfort and functionality, using current and emerging building technologies in new buildings makes it easier to approach the net-zero energy ideal.
Electricity and Energy Efficiency Retrofits of Existing Buildings
Reaching the extremes of energy efficiency is easier in new construction using the latest or revived ancient energy efficient techniques. One key policy measure for enhancing the future energy efficiency of buildings are national building standards that may be based on California’s Title 24, a system by which new construction is pushed to become more efficient with every successive generation of buildings. Just as in its utility laws, California now has 3 decades of experience in designing effective building laws from which most other states and the national government can draw in designing a broader system.
However for the next half a century or so, wherever we live, we will be living with many buildings that were built without much regard for their energy use. Many of these buildings can be made tighter and better insulated but will only in rare cases achieve the standards of hyperefficient new construction.
Buildings typically now draw their energy from a combination of wholesale generated electricity from the grid, piped-in natural gas, propane from tanks, and occasionally wood and wood pellets. It is unfortunate that fossil fuels predominate in this mix. As it turns out, if more buildings used electricity for more of their daily operations, building energy use could be halved for most energy intensive tasks. Furthermore, as the Renewable Electron Economy concept suggests, electrical energy which once came from fossil sources can be generated by renewable electric generators, thereby giving all-electric buildings the potential to be carbon neutral in their operations now or at some point in the future.
Furthermore, as we do not have the luxury of building an entire new building stock of near zero and net zero buildings from the ground up, high efficiency electric appliances and systems are fairly easy retrofits for existing buildings, though to implement these on a large scale sometimes requires an incentive structure to facilitate the move.
Heat Pumps: Ground Source, Hybrid Air/Ground, Air Source and BTES Linked
About 60% of the 40% of total US energy consumption (meaning 24% of total energy use) attributable to buldings is used by heating, ventilation and cooling systems, a.k.a space conditioning or HVAC, and water heating. Even in severe climates, this amount can be cut to half or less of current usage by the use of more efficient HVAC technologies most of which require only electricity as its energy input. Daily combustion of fossil fuels for space conditioning can be eliminated in most climates by the use of (electrically-driven) heat pumps that can pull heat out of or put heat into spaces as desired by building users. Heat pumps in combination with fans and water pumps distribute heat or cool either using an air-duct or a fluid-based radiant heat or cool distribution system in a building, thus can substitute for both an air conditioning and a heating system. Heat pumps operate using the same principle as a refrigerator but unlike a refrigerator can also work in reverse. Not only can energy use be cut by using properly designed heat pumps but dependence on natural gas and heating oil can be eliminated for space conditioning, allowing at some point in the future all energy for a building to come from renewable electric generators.
The most efficient, though highest price heat pumps used for space conditioning are ground source and groundwater source heat pumps (GSHPs) that use the substantial thermal mass, conductivity, and consistent year-round temperature of the ground or groundwater as either the heat source or the heat sink. The expense of GSHPs comes from the need to build a ground loop by trenching or by drilling boreholes several hundred feet deep through which a tube with a heat transfer fluid is drawn. The size of the GSHP’s ground loop has to do with the heating and cooling load and the soil characteristics. Sometimes called geothermal or geoexchange heat pumps, they can also use the excess heat that is extracted from the building or the ground to heat some of the hot water used in the building, though one could build a dedicated ground-source water heating loop as well for consistent all-year hot water heating.
GSHPs can reduce the energy needed to cool by half and to heat a house by as much as two-thirds with the energy requirements purely electric: the fan, compressor, and pump energy required to circulate the heat exchange fluid, extract the heat and distribute the heat or cool throughout the building. However, to reduce the size of the ground loop and therefore expense, it makes sense to tighten up and insulate the house.
Air-source heat pumps or hybrid air/ground heat pumps are less expensive than a ground source unit because they either have no ground loop (air-source) or a much shorter ground loop (hybrid). Less efficient than ground source units, these heat pumps are however good choices for milder climates and are improvements over electric resistance, oil and natural gas heat. Air source and air/ground heat pumps as well can be used to heat hot water further reducing the need for natural gas. For passive houses, the remaining heating and cooling load that cannot be fulfilled through passive means can be supplemented a number of ways but some use a micro ground loop under the house to extract and expel heat from the house may suffice, given the superinsulated nature of the house.
With the advent of borehole thermal energy storage, electric heat pumps can be used to deposit or extract heat from the seasonal thermal energy store, which will, in some applications, reduce the amount of energy required to condition buildings. These pumps do not require a compressor, thereby reducing the energy requirement for BTES.
Efficient (Gourmet) Electric Kitchens: Induction Cooktops and Electric Infrared Grilling
While space conditioning and water heating together account for 60% of the energy used by buildings in the US, another example of where a new electric technology can make substantial contributions to lowering building energy use is in the 4% of building energy used in cooking. Popular in Europe and growing in popularity in the US, magnetic induction cooking uses the induction effect of a high frequency magnet to heat the metal of a steel or iron pan or pot, thereby avoiding heating the surrounding air or the stovetop itself. Induction cooktops use 84% of the energy input to heat food as compared to 40% for gas or 70% for electric resistance cooktops. Furthermore induction cooktops are more minutely controllable, quicker, and safer as the cookware gets hot but the stove doesn’t.
The efficiency of induction cooktops combined with their functional advantages over gas will help electric cooktops and thereby all-electric kitchens gain market share over gas, which has been favored by demanding home cooks and chefs. The complaint that some chefs have that they cannot see the power and heat-setting of an induction cooktop as compared to gas can be easily overcome with the invention of a simple visual indicator of the power level for an induction stove.
While the attraction to open flames remains for many a signature of the cooking process, in the world of renewable fuels, charcoal and wood firing still produce the desirable flames, glow, chars and flavors that people have enjoyed for millenia. However, those in the grilling world who seek more convenience and less smoke for daily use, now prize the new infrared grilling technology, which can be fueled with natural gas, propane and now electric elements. The latter electric infrared grills can use renewably generated electricity and are easily controllable and more efficient than their fossil fuel equivalents. The further development and distribution of electric infrared grilling technology will allow all-electric cooking to reproduce or exceed the cooking results from fossil fuels with the same convenience.
While these issues may seem small, opting out of and eventually shutting down natural gas distribution to households and commercial kitchens without a decrease in end-user utility can help buildings become carbon neutral more quickly. Furthermore, the development of more efficient and cost-effective electricity-driven sources of heat can replace the use of natural gas for industrial processes which account for 8% of US total energy use.
Key Technologies for More Energy Efficient, Carbon Neutral Living
Including those mentioned above, listed below are some of the key technologies that will help us achieve energy independence and carbon neutrality more quickly.
1) Heat pumps: ground source, air source, hybrid and with bore hole thermal energy storage
2) Super-glass (low emissivity, selectively coated, insulated) and super-windows
3) High-R Insulation and structural insulated panels
4) Efficient Fluorescent and Efficient LED Lighting
5) Fiber-optic solar lighting and advanced skylights for daylighting
6) Intelligent building, lighting, and appliance controls
7) Light-colored and “cool-colored” building and paving materials (that reduce the heat island effect of the built environment and building heat loads)
‘8) Solar thermal water and space heating
9) Variable Frequency Drives (electronically adjusting pump and fan speeds to energy demand)
10) Weatherproofing and tighter building envelope standards (with testing)
11) Radiant heating (using water rather than air as the heat transfer medium in a building)
12) Induction cooktops, convection ovens and electric infrared grilling
Quality Assurance and Certification in Energy Efficiency
More so than in the generation of electricity or extraction of energy, the implementation of energy efficient technologies either through the private market or through government programs requires extensive testing by government or trusted 3rd party agencies to make sure that promised energy savings will be realized by a new technology. The potential for fraud in promising “more for less” or for improper installation of a technology requires oversight by both private and public regulators. Paired with the decoupling of utility revenues combined with a mandate to invest in energy efficiency, power utilities have an interest in monitoring the effectiveness of energy efficiency measures.
Energy Efficiency in Transport: Short term and Long-Term Solutions
One of the key features of the Renewable Electron Economy is the replacement of petroleum with electricity as the energy carrier for transportation. However this transfer will take place at varying speeds depending on the future cost and availability of petroleum as well as political support for electrification of transportation. Petroleum and natural gas will be around for at least a decade or two in force and in vestiges in the following decades. Increasing the efficiency of internal combustion drive vehicles will have a role even as we transition to vastly more efficient electric transport.
One of the motivations to transfer transport energy to electricity is the staggering increase in efficiency that electric motors represent over petroleum and natural-gas fueled internal combustion engines: the 90% efficiency of electric motors contrasts favorably with the 25-30% efficiency of the modern internal combustion engine. A vehicle of similar mass and design would have 3 or more times the mileage as an electric vehicle rather than a traditional petroleum-burning car.
In the first installment of this mini-series, I compiled a list of short-term solutions related to how we can reduce vehicle miles traveled rapidly by the more efficient operation of both our autonomous and public vehicle infrastructure and the use of information technologies. Below are some specific measures that can be applied to vehicles themselves.
While the internal combustion engine is near the end of its development trajectory, a number of innovators in the area of vehicle materials are attempting to show that the use of lightweight body materials such as carbon fiber can reduce conventional vehicle mass substantially without endangering vehicle safety. Amory Lovins has long championed the use of carbon fiber to double vehicle efficiency, claiming that bulky vehicles with advanced lightweight materials could have . The German company Loremo and the American company Aptera have also suggested radical, lightweight vehicle designs as ways to create hyperefficient vehicles that would either have a small internal combustion or an electric motor.
Vehicle Efficiency Standards and Automaker Penalties vs. Gas Taxes
Mandating vehicle efficiency standards has been an uphill battle in the US, requiring American automakers to work against their own design culture and the tendencies of American auto buyers to prefer large and powerful vehicles in an environment of cheap and abundant petroleum. While vehicle efficiency standards are, in the culture of environmental reform and public virtue, viewed to be a necessity to impress on upon both automakers and the public that optimality of fuel efficiency, higher gas taxes in Japan and European countries have been a far more effective means of compelling automakers and auto buyers to conserve energy and choose more efficient vehicles.
If US legislators and environmental pressure groups are at all serious about encouraging gasoline powered vehicles to use gasoline more wisely, they will need to challenge the Cheap Energy Contract with substantial rises in fuel taxes. This will take more courage on the part of these actors as simply asking for higher fuel efficiency standards puts the onus on automakers to lead the market. While the shortsightedness of US automakers is truly lamentable, legislators so far have not succeeded in transforming that culture through vehicle efficiency mandates. Those who cite the current success of Toyota and other foreign car makers vis-à-vis US makers forget that, among other things, the headquarters of these companies are in countries with fuel that costs at least twice as much as it does in the US. Fuel efficiency standards require US automakers to lead the efficiency charge, which requires them to occupy a position of moral and environmental leadership without the aide of high fuel prices.
A compromise that avoids some of the negative political fallout of an across the board gas tax hike is a varying tax surcharge that keeps the price of fuel above a certain level blocking efforts by oil producers to artificially lower prices or to smooth over the effects of temporary drops in demand. This fuel “price floor” would be explainable to constituents who should at some point understand that the movement to higher fuel prices is inevitable and energy efficiency in transport socially desirable.
Longer-term Measure: Shifting to Electric Drive
As discussed in the first installment of this series, the shift to electric drive is by far the most effective means of conserving energy resources. The current generation of hybrids use electric motors to provide an assist for relatively inefficient gasoline internal combustion engines. Plug in hybrids and electric vehicles have the potential to double or treble the efficiency of automobile drivetrains.
Price Signals and Energy Efficiency
Just as with the finance of new clean energy generation technologies, the price of energy is key in spurring energy efficiency investment and energy conservation. As indicated above, price signals are some of the most effective ways to spur private parties to cut their energy use; the implementation of those price signals through policy instruments needs to proceed at an urgent pace yet not so rapidly as to encourage backlash against the necessary efforts that we all must undertake to help preserve a favorable climate. Carbon taxes, fees and cap and trade systems will in all likelihood serve to spur investment in energy efficiency, though the degree to which they do will depend on the level of the resulting carbon price as well as the ultimate efficiency of the chosen mechanism. These instruments will in their early stages in all probability be more effective in spurring energy efficiency investments than they will in stimulating the building of new clean electricity generation as the relative cost of the latter is in many cases too high.