SACRAMENTO, Calif. —
Gov. Jerry Brown declared an end to California’s historic drought Friday, lifting emergency orders that had forced residents to stop running sprinklers as often and encouraged them to rip out thirsty lawns during the state’s driest four-year period on record.
The drought strained native fish that migrate up rivers and forced farmers in the nation’s leading agricultural state to rely heavily on groundwater, with some tearing out orchards. It also dried up wells, forcing hundreds of families in rural areas to drink bottled water and bathe from buckets.
Brown declared the drought emergency in 2014, and officials later ordered mandatory conservation for the first time in state history. Regulators last year relaxed the rules after a rainfall was close to normal.
But monster storms this winter erased nearly all signs of drought, blanketing the Sierra Nevada with deep snow, California’s key water source, and boosting reservoirs.
“This drought emergency is over, but the next drought could be around the corner,” Brown said in a statement. “Conservation must remain a way of life.” (2)
“In terms of assessing trends in globally-averaged surface air temperature as a metric to diagnose the radiative equilibrium of the Earth, the neglect of using moist enthalpy, therefore, necessarily produces an inaccurate metric, since the water vapor content of the surface air will generally have different temporal variability and trends than the air temperature.”
In our blog of July 11, we introduced the concept of moist enthalpy (see also Pielke, R.A. Sr., C. Davey, and J. Morgan, 2004: Assessing “global warming” with surface heat content. Eos, 85, No. 21, 210-211. ). This is an important climate change metric, since it illustrates why surface air temperature alone is inadequate to monitor trends of surface heating and cooling. Heat is measured in units of Joules. Degrees Celsius is an incomplete metric of heat.
Surface air moist enthalpy does capture the proper measure of heat. It is defined as CpT + Lq where Cp is the heat capacity of air at constant pressure, T is air temperature, L is the latent heat of phase change of water vapor, and q is the specific humidity of air. T is what we measure with a thermometer, while q is derived by measuring the wet bulb temperature (or, alternatively, dewpoint…
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The California Energy Commission has passed energy-efficiency standards for computers and monitors in an effort to reduce power costs, becoming the first state in the nation to adopt such rules. Th…
There are many metrics and measurements when it comes to evaluating energy as we use it in our daily lives. In order to compare between different sources or end uses we often have to make conversions in our terms so that our comparisons are equitable. This may be further complicated as different countries often use different standards of measure, however, we will convert to common units.
Benchmarking is the practice of comparing the measured performance of a device, process, facility, or organization to itself, its peers, or established norms, with the goal of informing and motivating performance improvement. When applied to building energy use, benchmarking serves as a mechanism to measure energy performance of a single building over time, relative to other similar buildings, or to modeled simulations of a reference building built to a specific standard (such as an energy code). (1)
Benchmarking is a common practice in buildings to establish existing consumption rates and to identify areas that require improvement and to help prioritize improvement projects. These benchmarks can be established for a building, system within a building, or even a larger campus, facility or power source. Usually an energy or facility manager will determine energy consumption over a fixed period of time, 1 to 3 years, and compare it to similar facilities. Normalized by gross square footage of the building the EUI is usually expressed as kBtu/sf per year.
Energy Intensity (EI) of a Country
Figure 1: Energy Intensity of different economies The graph shows the amount of energy it takes to produce a US $ of GNP for selected countries. (2)
Not to be confused with Energy Use Intensity, Energy Intensity is an economic measure of energy use normalized by the GDP of a country and is considered a measure of a Nation’s Energy Efficiency. Countries with a high EI have a higher cost to convert energy into GDP, whereas countries with low EI have lower costs of converting energy into GDP. Many factors contribute to the EI value, including climate, energy sources and economic productivity. (2)
Energy Use Intensity (EUI)
The EUI of a building includes the electrical power use and heating fuel consumption for heating and hot water generation. Many facilities require different loads according to their primary use or function, including cooling and refrigeration. For the comfort of occupants electricity is needed for lighting and plug loads to meet the functioning needs of the equipment in the facility. Heating, ventilation and air conditioning (HVAC) may require electricity or another fuel such as natural gas. Hot water may be generated with electricity or a fuel. A site may also have solar PV or hot water, wind power, and daylighting programs. There are also many strategies which may be employed by building operators to reduce loads and energy consumption including controls, storage, micro-grid, purchasing offsets, etc.
When comparing buildings, people not only talk about total energy demands, but also talk about “energy use intensity” (EUI). Energy intensiveness is simply energy demand per unit area of the building’s floorplan, usually in square meters or square feet. This allows you to compare the energy demand of buildings that are different sizes, so you can see which performs better.
EUI is a particularly useful metric for setting energy use benchmarks and goals. The EUI usually varies quite a bit based on the building program, the climate, and the building size. (3)
Figure 2. Typical EUI for selected buildings. This graph is based on research EPA conducted on more than 100,000 buildings (4)
Site Energy vs Source Energy
As we go forward into the future, it is rather unclear how current events will affect the international agreements on reducing carbon consumption. However, generally speaking, renewable energy sources are seen to becoming more economic for power production. For many facilities this means that supplementing existing grid sources for power with on-site power production is making economic sense. Future building improvements may include sub-systems, batteries and energy storage schemes, renewable sources or automated or advanced control systems to reduce reliance on grid sourced power.
The energy intensity values in the tables above only consider the amount of electricity and fuel that are used on-site (“secondary” or “site” energy). They do not consider the fuel consumed to generate that heat or electricity. Many building codes and some tabulations of EUI attempt to capture the total impact of delivering energy to a building by defining the term “primary” or “source” energy which includes the fuel used to generate power on-site or at a power plant far away.
When measuring energy used to provide thermal or visual comfort, site energy is the most useful measurement. But when measuring total energy usage to determine environmental impacts, the source energy is the more accurate measurement.
Sometimes low on-site energy use actually causes more energy use upstream. For example, 2 kWh of natural gas burned on-site for heat might seem worse than 1 kWh of electricity used on-site to provide the same heating with a heat pump. However, 1 kWh of site electricity from the average US electrical grid is equal to 3.3 kWh of source energy, because of inefficiencies in power plants that burn fuel for electricity, and because of small losses in transmission lines. So in fact the 2 kWh of natural gas burned on site is better for heating. The table below provides the conversion factors assumed by the US Environmental Protection Agency for converting between site and source energy. (3)
(1) BUILDING ENERGY USE BENCHMARKING https://energy.gov/eere/slsc/building-energy-use-benchmarking
(2) ENERGY INTENSITY https://en.wikipedia.org/wiki/Energy_intensity
(3) MEASURING BUILDING ENERGY USE https://sustainabilityworkshop.autodesk.com/buildings/measuring-building-energy-use
(4) WHAT IS ENERGY USE INTENSITY (EUI)? https://www.energystar.gov/buildings/facility-owners-and-managers/existing-buildings/use-portfolio-manager/understand-metrics/what-energy
Can the idea of sustainability be determined by metrics? The answer is “Of course”, as any type of improvement can be measured. We understand it is far more efficient to recycle aluminum than it is to produce it the first time, which we call this value embodied energy. However, since refining represents a significant proportion of manufactured costs there becomes a premium on recycling used aluminum. Not only are the savings in energy, they are also in emissions of GHG’s.
“Recycling aluminum produces 95 percent fewer greenhouse gas (GHG) emissions and requires 95 percent less energy than primary aluminum production, enabling Novelis to achieve lower GHG emissions despite increasing global production capacity.” (1)
Novelis also reports improvements in Energy Intensity and Water Intensity metrics.
Significant gains were also made in fiscal 2016 as it relates to water and energy intensity. Novelis achieved a 22 percent reduction in water intensity and a 24 percent reduction in energy intensity for the 2007-2009 baseline. (1)
Novelis Core Business
Novelis produces close to 20 percent of the world’s rolled aluminum products and we are strategically located on the four continents where aluminum demand is the greatest: North America, South America, Europe and Asia. Our dedication, innovation and leadership have made us the number one producer of rolled aluminum in Europe and South America, and the number two producer in North America and Asia. We also are the world’s largest recycler of used beverage cans, which comprise a critical input to our operations. Quite simply, recycling is a core element of our manufacturing process. (2)
Figure 1: Novelis Opens World’s Largest Aluminium Recycling Facility (3)
Novelis has officially opened the “world’s largest” aluminium recycling centre located adjacent to the company’s rolling mill in Nachterstedt, Germany and costing over £155m.
The recycling centre will process up to 400,000 metric tons of aluminium scrap annually, turning it back into high-value aluminium ingots to feed the company’s European manufacturing network.
“The Nachterstedt Recycling Centre is a significant step toward our goal to be the world’s low-carbon aluminium sheet producer, shifting our business model from a traditional linear approach to an increasingly closed-loop model,” said Phil Martens, president and chief executive officer of Novelis. (3)
As gridlock continues to be a problem in the United States, exacerbated by crumbling infrastructure, the American public has reportedly approved up to $200 billion for rapid and mass transit.
According to the American Public Transportation Association (Apta), the 49 ballot measures totalling nearly $US 200bn that were voted on were the largest in history. […]
The largest measure in the country, Los Angeles County’s Measure M, was passed with 69% approval with all precincts reporting. The sales tax increase needed a two-thirds majority to pass and is expected to raise $US 120bn over 40 years to help fund transport improvement projects, including Los Angeles County Metropolitan Transportation Authority (LACMTA) schemes to connect Los Angeles International Airport to LACMTA’s Green Line, Crenshaw/LAX line and bus services; extend the Purple Line metro to Westwood; extend the Gold Line 11.7km; extend the Crenshaw Line north to West Hollywood; and build a 6.1km downtown light rail line. The measure will also provide $US 29.9bn towards rail and bus operations, and $US 1.9bn for regional rail.
California’s other big transit wins include Measure RR in the San Francisco Bay area, which will authorise $US 3.5bn in bonds for Bay Area Rapid Transit rehabilitation and modernisation. It required a cumulative two-thirds vote in San Francisco, Alameda and Contra Costa counties for passage and received 70% approval. (1)
Figure 1. Bay Area Rapid Transit (2)
BART’s Focus on Material Conservation, Energy Savings and Sustainability
BART’s infrastructure requires the train cars to be extremely lightweight. To meet this requirement, most of the exterior of the new train cars will be constructed out of aluminum. Aluminum is abundant, doesn’t rust, and when properly finished, reflects heat and light, keeping the train cars cool. It is lightweight but strong, yet fairly easy to work with, reducing the energy investment during the manufacturing process. Additionally, aluminum is easily and readily recyclable, making it very low impact when the train cars are eventually retired and dismantled. (2)
Federal Investment in Rapid Transit and Transportation Infrastructure Lagging
Yet, despite the public’s continued desire to see greater investment in transit, historically transit has received only a small minority of funding at the federal level. Currently, only 20 percent of available federal transportation funds are invested in transit and just 1 percent of funds are invested in biking and walking infrastructure. Meanwhile, 80 percent of federal transportation dollars continue to be spent on roads.
“While many localities recognize the need to invest in transit, biking, and pedestrian solutions that can bring our transportation system into the 21st century, federal officials remain woefully behind the curve,” said Olivieri. “While it is great to see such widespread support of transit at the local level, the need for these measures speaks volumes about how out of sync federal decision makers are with the wants and needs of the American people,” he added.
The nation currently faces an $86 billion transit maintenance repair backlog, while data from the Federal Highway Administration’s National Bridge Inventory show that despite the large discrepancy at the federal level between investment in transit and spending on roads, the nation’s road system is in similarly bad shape. To date, more than 58,000 bridges remain structurally deficient.
“Despite the fact that roads receive 80 percent of available federal transportation dollars, both transit and roads continue to face enormous repair and maintenance backlogs,” said Lauren Aragon, Transportation Fellow at U.S. PIRG. “While the overall level of funding is important, how states spend the limited federal funding they receive can have even greater consequences but states continue to funnel road funding into new and wider highway projects, leaving the existing system to crumble. We need to fix what we have already built first,” she added. (3)
Figure 2. Typical image of steel bridge in disrepair (4)
Harvard Business Review Reports on Crumbling American Infrastructure
Bridges are crumbling, buses are past their prime, roads badly need repair, airports look shabby, trains can’t reach high speeds, and traffic congestion plagues every city. How could an advanced country, once the model for the world’s most modern transportation innovations, slip so badly?
The glory years were decades ago. Since then, other countries surpassed the U.S. in ease of getting around, which has implications for businesses and quality of life. For example, Japan just celebrated the 50thanniversary of its famed bullet train network, the Shinkansen. Those trains routinely operate at speeds of 150 to 200 miles per hour, and in 2012, the average deviation from schedule was a miniscule 36 seconds. Fifty years later, the U.S. doesn’t have anything like that. Amtrak’s “high-speed” Acela between Washington, D.C., and Boston can get up to full speed of 150 mph only for a short stretch in Rhode Island and Massachusetts, because it is plagued by curves in tracks laid over a century ago and aging components, such as some electric overhead wiring dating to the early 1900s.
Numerous problems plague businesses and consumers: Goods are delayed at clogged ports. Delayed or cancelled flights cost the U.S. economy an estimated $30-40 billion per year – not to mention ill will of disgruntled passengers. The average American wastes 38 hours a year stuck in traffic. This amounts to 5.5 billion hours in lost U.S. productivity annually, 2.9 gallons of wasted fuel, and a public health cost of pollution of about $15 billion per year, according to Harvard School of Public Health researchers. The average family of four spends as much as 19% of its household budget on transportation. But inequality also kicks in: the poor can’t afford cars, yet are concentrated in places without access to public transportation. To top it all, federal funding for highways, with a portion for mass transit, is about to run out. (4)
(1) Nearly 70% of US transit ballot measures pass; http://www.railjournal.com/index.php/north-america/nearly-70-of-us-transit-ballot-measures-pass.html
(2) BART – New Train Car Project; http://www.bart.gov/about/projects/cars/sustainability
(3) BILLIONS IN TRANSIT BALLOT INITIATIVES GET GREEN LIGHT; http://www.uspirg.org/news/usp/billions-transit-ballot-initiatives-get-green-light
(4) What It Will Take to Fix America’s Crumbling Infrastructure; https://hbr.org/2015/05/what-it-will-take-to-fix-americas-crumbling-infrastructure
You’ve heard the good news on climate: after a century or more of continuous rise, U.S. CO2 emissions have finally begun to decline, due largely to changes in the energy sector. According to the Energy Information Agency (EIA), energy-related CO2 emissions in 2015 were 12% below their 2005 levels. The EIA says this is “because of the decreased use of coal and the increased use of natural gas for electricity generation.”
Is the EIA right in making natural gas the hero of the CO2 story? Hardly. Sure, coal-to-gas switching is real. But take a look at this graph showing the contributors to declining carbon emissions. Natural gas displacement of coal accounts for only about a third of the decrease in CO2 emissions.
By far the biggest driver of the declining emissions is energy efficiency. Americans…
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Before discussing any aspect of energy technology one should give a definition of energy. Most textbooks on energy technology do not go down to this fundamental level. The authors may have worked o…
Source: Defining energy and exergy
When we think of using electricity one of the prevalent uses is to provide a heat source. We see this in our everyday lives as ranges and ovens, microwaves, kettles, hot water tanks, baseboard heaters, as well as other applications. So how about reversing the process and capturing heat and directly converting to electricity, is this possible? As it happens there is a classification of materials which have a property called a thermoelectric effect.
Boosting energy efficiency is an important element of the transition to a sustainable energy system. There are big savings to be made. For example, less than half the energy content of diesel is actually used to power a diesel truck. The rest is lost, mostly in the form of heat. Many industrial processes also deal with the problem of excessive waste heat.
That’s why many research teams are working to develop thermoelectric materials – materials that can convert waste heat into energy. But it’s no easy task. To efficiently convert heat to electricity, the materials need to be good at conducting electricity, but at the same time poor at conducting heat. For many materials, that’s a contradiction in terms.
“One particular challenge is creating thermoelectric materials that are so stable that they work well at high temperatures,” says Anders Palmqvist, professor of materials chemistry, who is conducting research on thermoelectric materials. (1)
Image 1: The enlarged illustration (in the circle) shows a 2D electron gas on the surface of a zinc oxide semiconductor. When exposed to a temperature difference, the 2D region exhibits a significantly higher thermoelectric performance compared to that of bulk zinc oxide. The bottom figure shows that the electronic density of states distribution is quantized for 2D and continuous for 3D materials. Credit: Shimizu et al. ©2016 PNAS
The thermoelectric effect is not as efficient as converting electricity to heat, which is generally 100% efficient. However, with waste energy streams even a small conversion rate may return a significant flow of usable electricity which would normally go up a stack or out a tailpipe.
The large amount of waste heat produced by power plants and automobile engines can be converted into electricity due to the thermoelectric effect, a physics effect that converts temperature differences into electrical energy. Now in a new study, researchers have confirmed theoretical predictions that two-dimensional (2D) materials—those that are as thin as a single nanometer—exhibit a significantly higher thermoelectric effect than three-dimensional (3D) materials, which are typically used for these applications.
The study, which is published in a recent issue of the Proceedings of the National Academy of Sciences by Sunao Shimizu et al., could provide a way to improve the recycling of waste heat into useful energy.
Previous research has predicted that 2D materials should have better thermoelectric properties than 3D materials because the electrons in 2D materials are more tightly confined in a much smaller space. This confinement effect changes the way that the electrons can arrange themselves. In 3D materials, this arrangement (called the density of states distribution) is continuous, but in 2D materials, this distribution becomes quantized—only certain values are allowed. At certain densities, the quantization means that less energy is required to move electrons around, which in turn increases the efficiency with which the material can convert heat into electrical energy. (2)
Photo of Arbutus Mall, Vancouver
As an engineer and self-proclaimed entrepreneur I find myself value driven when seeking opportunities. Usually value is something which can measured, whether it be in profit, market share, response rate, efficiency in operations and resource management, or other metric. It may be to date unrecognized or otherwise under-utilized or untapped resource which can be subject to improvements or other opportunities.
Education of the market can be a daunting task, and getting recognition may be challenging. However, perseverance and targeted marketing can eventually lead to opportunities where value can be recognized in a structured manner where a service contract may be offered to complete the scope of the determined project. Here are some personal thoughts that I am putting down in a Q/A format:
Q. Why do I write a blog?
A. Writing a blog on energy in our built and constructed world has multiple benefits. I get to practice my writing and research skills, learn new and emerging technology, meet new people, continue my growth as an individual and professional, and publish my research.
Q. Why do I write about energy?
A. One of the reasons I choose energy conservation and efficiency is my own understanding of how we can rationalize construction projects and work by building operations savings. In the past with failing mechanical systems in buildings I have specified upgrades to the building plant to improve operations and partially pay for the repairs and upgrades by operational savings.
Q. What kind of professional services are needed in buildings?
A. To start we must to perform baseline measurements of the building. Before changes are made so as to establish existing consumption rates of energy and water, as well as waste streams. By doing this we can examine methods of reducing consumption rates and establish priorities for improvements and budget proposals for improvements in building equipment, the building envelope, electrical and lighting, as well as fixing ongoing problems or other deficiencies. Generally speaking, a building energy audit and report is proposed start to this process, where an informal meeting with building staff, obtaining existing plans and doing an initial onsite inspection of operations and systems.
Q. How can we achieve energy savings and be more green?
A. Small and local things can add up, this is a fundamental tenet of conservation. Every act gets examined, where is the waste, what can be reduced, is it needed, how can we do this differently. All questions need to be asked and answered where an environment is occupied, and can be quite intensive where industry or other energy intensive commercial enterprise may be involved.
Q. Why do I need an outside consultant or professional to perform this work?
A. There are many tools a consultant can use and bring to the table with a client. Knowledge and understanding of systems are important and how they fit together, someone who has experience in systems design, has worked in the field and can provide a service to either establish an initial plan to overseeing the entire project, including design, execution and final occupancy.
Q. What else is important besides an energy audit?
A. After an energy audit, building condition review and report may follow a request for proposal if it is determined by the client that repairs are required and a budget for these may be established prior to commencing work. Within the proposal will be a preliminary scope or statement of work.