Over the last decade, the renewable energy industry has boomed due to the proliferation of new technology that is reducing the cost of construction and long-term operability. However, one critical problem still remains: storing renewable energy during lulls in wind speed or sun exposure is often prohibitively expensive. In response to this issue, Energy Vault, a subsidiary of California’s IdeaLab, has recently announced a straightforward mechanism for the conservation of renewable sources using kinetic forces. The mechanism proposed by Energy Vault is a nearly 400-foot tall, six-armed steel crane. Using proprietary software, the towering structure orchestrates the placement of 35-ton blocks of concrete in response to drop-offs in demand and fluctuations in environmental conditions. How does it work? As power demand decreases, the cranes surround themselves with concentric rings of the concrete bricks lifted by the leftover power from surrounding wind and solar farms. Once demand increases, the cranes begin lowering the bricks, which powers turbines that transform the kinetic energy into electricity that gets pumped back into the grid. Energy Vault’s team looked toward preexisting renewable energy sources that rely on gravitational forces. According to Energy Vault, the technology was influenced by energy retention strategies of hydroelectric power dams that pump water into a series of cisterns on higher ground that ultimately flow downwards into energy turbines once demand rises. Unlike conventional resources used for the retention of renewable energy, such as Tesla’s Powerwall and Powerpack lithium-ion stationary batteries, the system developed by Energy Vault does not rely on chemical storage solutions or high-cost materials. Recycled debris from preexisting construction sites can be used for the fabrication of the bricks, which are viable for up to four decades without a decrease in storage capacity. Currently, Energy Vault is partnering with India’s Tata Power Company Limited to construct an initial 35 MWh system with an expected date of completion in 2019.
Posts tagged with "renewable energy":
The city council of Spokane, Washington, has adopted a new ordinance that would make it the second city in the state after Seattle to set the goal of being powered entirely with renewable energy by 2030. The so-called Fossil Free Spokane initiative will create a new Sustainability Action Commission in the city that will update Spokane’s Sustainability Action Plan to include a specific climate action roadmap aimed at reducing its fossil fuel consumption down to zero. The plan aims to do so by deploying a mix of community-benefitting sustainable energy initiatives that include creating a low-income solar program, expanding regional access to clean transit, and working with local utility providers to transition to renewable generation methods. “Creating an electrical grid from 100 percent renewable energy is urgent, but requires collaboration across all sectors,” said Spokane council member Breean Beggs during a recent meeting. Beggs added that work was already underway with local utility Avista to “create a pragmatic and cost-effective approach to upgrading Spokane’s electrical grid.” The pledge will bring the number of American cities vying for 100 percent renewable energy generation to 79, a group that includes large, medium, and small-sized cities, including Salt Lake City, Utah, Sarasota, Florida, St. Louis, Missouri, San Diego, California, and Concord, New Hampshire. These cities are all aiming to derive all of their energy from renewable resourced by 2030 or 2032, according to the Sierra Club. At the county level, nine counties have made the pledge, including Multnomah County, Oregon, Buncombe County, North Carolina, and Pueblo County, Colorado. The state of Hawaii has signed on to a similar promise, as well. Though it might seem like a pie-in-the-sky effort, five smaller American cities have already hit this lofty goal. Those cities are Aspen, Colorado, Burlington, Vermont, Greensburg, Kansas, Rock Port, Missouri, and Kodiak Island, Alaska. A recent report by the environmental group CDP found that over 100 cities worldwide generate a majority—over 70 percent—of their power from renewable sources, up from just 42 in 2015. The report found that 40 cities worldwide are entirely powered by clean energy and that investment in renewable energy sources was highest across Europe, Africa, and Latin America, where billions of dollars in recent clean energy investments are remaking the energy portfolios around the world following the signing of the Paris Agreement in 2015.
The power utility company serving Traverse City, Michigan, a small city in the north of the state, has decided to shift completely to renewable energy sources. The board of Traverse City Light & Power (TCL&P) decided this month that they would aim to make the shift by 2040, the Traverse City Record Eagle reported last week. Dozens of towns and cities across the country have made similar pledges in the years since President Trump pulled the U.S. out of the 2015 Paris Climate Agreement last year. According to the Record Eagle, Traverse City mayor Jim Carruthers had already announced that all of the city's municipal operations would be renewably powered by 2020. What distinguishes this step is that the utility company is exceeding goals set by the city it serves. Towns and cities rely on utility companies to provide electricity. These utilities, in turn, contract suppliers who generate electricity through a variety of means. When municipalities set green energy goals, that leaves utility companies scrambling to find providers who can fulfill the demand. In the Traverse City case, however, the utility company is deciding to ditch polluting sources before its customers have. The impact may not be enormous—TCL&P serves a region with a population less than 20,000—but it is an example of how utilities could evolve in other areas, and what customers could reasonably demand from their utility companies. As older fossil fuel power plants age out of use, utilities are sometimes confronted with a choice over whether to replace the loss from a similar source or to go after newer, sustainable solutions. The Record Eagle reported that two coal plants that currently supply TCL&P are scheduled to go offline by 2030, and that new wind farms on the Great Lakes could be potential replacements. The article also said that the decision was nearly unanimous among the utility's board, with only one member warning rising costs.
The stretch of I-20 between Abilene and Midland-Odessa, Texas, passes through what might be the most thoroughly harnessed land in the U.S. Here, the exploitation is complete: Water is pumped from aquifers and used to irrigate corn, cotton, and sorghum fields on the surface, where cattle and poultry are also raised; oil and natural gas are mined from the Permian Basin, the most productive such reservoir in the country, and home, some believe, to trillions more barrels of oil and cubic feet of gas; and thousands of wind farms fill the horizon, the most concentrated part of a statewide infrastructure that nominally churns out 22,637 MW per hour, which is more than any other state. While each of these components is remarkable in itself, the layering of them within a single landscape is sublimely breathtaking. Oil and gas pump jacks and refineries, tanker trains and semi-trucks, water towers and windmills, agricultural fields and center pivot linear irrigation systems, wind turbines and transmission lines create a sci-fi tableau reminiscent of fantasies about terraforming other planets, especially when this scene is compared to the relatively barren desert to the west and south. In this part of West Texas it is possible to see the Anthropocene writ large.
Let’s face it: no one has ever characterized a solar panel as being particularly attractive. In fact, they’re eyesores. While the environmental and business cases for photovoltaics are relatively easy to make, their aesthetic dimension has long been a losing proposition. “In states like California, solar is half the price of the local utility, even without subsidies,” explained Ido Salama, co-founder of Sistine Solar. “At the same time, it feels like all solar products look the same: they come in either black or blue, and, while solar panels work great, many people would describe them as ugly. At the very least, they look out of place on a roof,” he added. Rather than attempting to convince people to appreciate solar for what it is, Salama and company set out to build a solar panel that appeals to their sense of aesthetics instead. To that end, Sistine Solar introduced its SolarSkin technology—described on the company’s website as “solar with curb appeal”—in 2013 when its developers won the renewables track of the MIT Clean Energy Prize. Since launching SolarSkin, the company recently introduced its online Design Studio platform to allow anyone to design, customize, and price a solar installation.
How it worksDeveloped by MIT engineers, SolarSkin is a thin film specially coated with ultra-durable graphics and integrated onto high-efficiency solar panels. The technology employs selective light filtration to simultaneously display an image and transmit sunlight to the underlying solar cells with minimal loss in efficiency. The product is available in any number of colors and patterns, is compatible with every major panel manufacturer, and is available for both new and existing roofs. The end result is essentially a kind of camouflage for the typically drab photovoltaic panel. Sistine Solar’s new SolarSkin Design Studio is an online tool that allows architects, designers, and homeowners alike to design and order a customized solar system from a desktop computer or mobile phone. With a $99 refundable deposit, end users will receive a preliminary system design using LIDAR mapping, a detailed panel layout, guaranteed production figures, a realistic rendering, (where suitable image is available), and guaranteed delivery within 90 days. The Design Studio is intended to get customers more excited about solar, according to Salama. “Homeowners appreciate the transparency, customizability, and especially the ability to match their solar panels to their roof,” he said. “Architects and designers love it because for the first time, they have a product that allows them to showcase solar in a way never before possible—integrated, congruent, harmonious." In spite of the improvement to aesthetics, however, solar technology still faces a number of challenges in terms of market transformation. “Soft costs is one barrier,” he said. “Solar is so complex because every municipality has different rules when it comes to permitting solar.” Noting that it may take one to three days to physically install and wire up a solar system, Salama points out that it can take up to three months to get a permit. “If soft costs could be reduced—like streamlining the permitting process—we would see a radical transformation in adoption,” he suggested. Of course, affordable storage is an ongoing issue with solar technology. “When solar and storage become more economical than buying from the local utility, we will see a huge shift towards distributed generation and plenty of homeowners cutting the cord,” Salama predicted. Now that solar panels are eligible for a makeover, however, there’s one less hurdle to overcome—making the future of solar technology a little more attractive.
The New York Times journalist Thomas Friedman once asked, “Do you know what my favorite renewable fuel is? An ecosystem for innovation.” If you pose the same question to Pavegen founder and CEO Laurence Kemball-Cook, his answer would most likely be: foot traffic. That’s because Kemball-Cook, who is passionate about climate change, believes “technology alone won’t make cities perform more efficiently. It’s about changing behaviors.” To that end, he spent time developing renewable energy solutions in built-up urban environments and ultimately landed on the idea of capturing ambient energy from people and footfall. After testing a series of prototypes, Kemball-Cook jumped in feet first and launched Pavegen, a company that harvests energy and data from foot traffic. Building a complex technological product that operates reliably in all physical conditions isn’t easy, however. City streets are constantly undergoing challenges, from extreme temperature variations to a wide range of forces and impacts, Kemball-Cook explained. “Engineering this versatility into our system has been a big challenge, and it has been a highly iterative process to get to where our design is today,” he said.
How it worksAt its core, Pavegen technology is a multi-functional, custom flooring system that transforms foot traffic into off-grid electricity. As pedestrians walk across the system, the weight from their steps creates a vertical movement in the top surface between 5 and 10 millimeters. Electromagnetic generators below the surface compress, creating a rotary motion which produces 2 to 4 joules of energy per step, or roughly 5 watts of continuous power which can be stored in batteries or deployed locally to power applications such as lighting, sensors, and data transmission. Pavegen’s latest model, the V3, features a unique, triangular configuration that enables the tiles’ connected surface to move as a whole. As a result, Kemball-Cook says the formation enables a generator to be placed under each point of the tiles, which translates into greater energy converted per square foot than previous models—200 times more than initial prototypes, in fact. Further, the size of the triangles and the amount of resistance in the flywheels have been modeled using data on the length, speed, and force of human steps. “We use this information to maximize efficiency, and capture most of the available energy from footfall to produce a steady stream of off-grid energy and data.” Additionally, the Pavegen system is able to connect to a range of mobile devices and building management systems. “As well as energy, our systems also provide data on energy output and can connect to users’ smartphones via low-power Bluetooth beacons,” Kemball-Cook said. “We have an app where people can see how much electrical energy they are generating and convert this into rewards, which also generates valuable relationship data.” Ultimately, strengthening the relationship between people and the environment is what Pavegen is all about. “Our technology enables people to directly engage with clean energy, to increase their understanding of sustainability issues, and to generate useful off-grid energy,” he said. “Pavegen’s combination of physical interactivity and rich data is helping to bring smart cities to life. Forget the Internet of Things, we’re building the Internet of Beings.” [youtube https://www.youtube.com/watch?v=_sby4GR0sD8]
Chicago Mayor Rahm Emanuel, along with other top city officials, has announced the city’s intention to power every one of its public buildings with 100% renewable energy by 2025. This would make Chicago the largest city in the U.S. to power its properties with renewable energy. The announcement comes in direct opposition to recent policy proposals put forward by the Trump administration. “As the Trump administration pulls back on building a clean energy economy, Chicago is doubling down,” Mayor Emanuel said. “By committing the energy used to power our public buildings to wind and solar energy, we are sending a clear signal that we remain committed to building a 21st-century economy here in Chicago.” The announcement was made atop the roof of the Shedd Aquarium, which is not a public building, but recently installed 900 solar panels. The Shedd is participating in the mayors Retrofit Chicago Energy Challenge, which also involves installing high-efficiency lighting and large on-site batteries. The combined energy use of the city’s buildings in 2016 was approximately 1.8 billion kilowatt-hours, which accounts for about 8% of the city’s total electricity use. This is also the equivalent of powering about 295,000 Chicago homes for the same amount of time. In recent years, the city has made significant moves towards its renewable energy goals by eliminating coal use from over one billion kilowatt hours in 2013 alone. The city also reduced its carbon emissions by 7% between 2010 and 2015. Chicago was also named the 2017 ENERGY STAR Partner of the Year Award winner by the U.S. Environmental Protection Agency. "Today's action is a historic step forward in establishing Chicago as a clean energy leader,” said Jack Darin, Illinois Sierra Club President. “By moving boldly to repower its public buildings with renewable energy like wind and solar, Chicago is leading by example at a time when local leadership is more important than ever. While President Trump and his administration would reverse America's progress on climate change and clean energy, Mayor Emanuel is ensuring that Chicago will move forward, and that its residents will benefit from the good jobs and cleaner air that come from renewable energy projects. We look forward to working with the Mayor, community leaders, and the people of Chicago to achieve this bold goal on the path to eventually powering all of Chicago with 100% clean energy."
French authorities have announced that it plans to lay over 600 miles of solar roads within five years. Research from a five year study in collaboration with highway company COLAS indicates that the roads could provide power to up to 5 million people, or 8 percent of France's population. However, some claim that the French government is merely subsidising French companies and not following the best road for alternative energy solutions. Project "Wattway," as it is being called, was launched last October with the French Agency of Environment and Energy Management stating that just over 13 feet (4m) of solar road (215 square feet to be precise) could meet the energy demands (except heating) of one home. On that basis, 5,000 residents could draw on their energy supplies from as little as 0.62 miles of solar road. https://twitter.com/RoyalSegolene/status/693861761179611136?ref_src=twsrc%5Etfw Five years of research deduced that French roads are only occupied by vehicles "10 percent of the time" and that the solution could pave the way for solving future energy demands. Looking at the specs, the surface uses polycrystalline silicon cells, which are "encapsulated in a substrate," forming high yield solar panels. Only 0.28 inches (7mm) thin, the panels have an extremely high strength-to-weight ratio which allows them to deal with the weight of pretty much all motor-vehicles. For those thinking that driving on solar panels has the potential to be hazardous, fear not. Snowplow tests have been passed and the panels com equipped with all-weather skid-resistant coating. “These extremely fragile photovoltaic cells are coated in a multilayer substrate composed of resins and polymers, translucent enough to allow sunlight to pass through, and resistant enough to withstand truck traffic,” said COLAS. It's not just homes the roads could potentially power. Outlining the possibilities for "intelligent roads," COLAS said how they could be used for real time traffic management, self-driving cars, charging moving electric vehicles and eliminating black ice. What's more, COLAS said that the panels can be "directly applied to existing roads, highways, bike paths, parking areas, etc., without any civil engineering work." On top of that, the panels can last up to 20 years in areas that see infrequent traffic, meanwhile COLAS estimates the lifespan of the panels in regular traffic conditions to be 10 years. For example, if the quickest route from Caen in the North of France down to Marseille were to be covered, residents in both cities could be powered for 52 years if the panelled road lasted 10 years (and was removed afterwards). How Legitimate are COLAS's claims? France gets 1,600–2,000 sunlight hours per year. Taking the minimum of that, and subtracting 10 percent (road occupancy from vehicles) that leaves 1,440 sunlight hours per year. Interestingly, COLAS's claim of powering one home every 13 feet arose from the presumption of roads receiving only 1,000 sunlight hours per year, indicating that they are being extremely stringent with their study. Unsurprisingly, COLAS's panels have a lower percentage yield than current photovoltaic market solutions, offering 15 percent solar yields compared to 19 percent, but one can presume that this is a byproduct of making the panels roadworthy and their altered angle of incidence. This equates (by COLAS' calculations) to the panels costing $6.73 per Watt. However, according to Olivier Danielo of DDMagazine, this is "six times the cost "of large-scale photovoltaic cells." Danielo has reason to be skeptical. COLAS specialize in highway construction and by creating an "energy efficient" solution actually implement roads that have a shorter lifespan than regular roads, thereby giving themselves more work. Surely it would be far more efficient to equip houses who can utilize the optimum angle of incidence in conjunction with the most efficient photovoltaic (PV) technology? Jenny Chase, head of solar analysis at Bloomberg New Energy Finance ("Solar Insight Team") backs Danielo's claims up. https://twitter.com/solar_chase/status/696658947252609024 Danielo and Chase aren't the only ones concerned, either. French engineer Nicolas Ott said that the energy payback from rooftop PV's is 7.5:1 compared to Wattway's 1.6:1. COLAS also claim to have "invented" the solar road when this is not the case. SolaRoad, a bike path in Krommanie in the Netherlands produced better than expected yields. However, when compared to three rooftop PV systems in the same area of the prototype road, data showed that rooftop PV's was double that of the SolaRoad per square meter over the same period. https://www.youtube.com/watch?v=6-ZSXB3KDF0 Nonetheless, installation of the French solar road panels is set to start soon with funding coming from raising taxes on fossil fuels. https://www.youtube.com/watch?v=8ZNJhcNq9q4
Fossil fuel dependency is now a thing of the past for this municipality on Colorado's Western Slope. Aspen has just announced that it's only the third city to kick the habit and is fully reliant on renewable energy sources. Earlier this month, the Aspen Times reported that the city had reached the landmark after it signed a contract with electrical energy provider Municipal Energy Agency of Nebraska. As part of this process Aspen swapped coal for wind power to make up for the non-renewable energy deficit with its energy also coming from hydroelectric, solar, and geothermal. Prior to this, Aspen had been running on an estimated 75 to 80 percent renewables. The feat was also able to be realized due to the recent drop in solar energy prices. In fact, the cost of solar energy is predicted to fall further still, dropping below $0.50 per watt in the next few years. Solar energy is not alone in this trend. In what's a good economic indicator of renewable energy's growing popularity, wind power is also much cheaper than it was just a decade ago. This trend toward renewables was likely aided by Obama's carbon regulations which made renewable energy alternatives increasingly competitive against fossil fuel sources such as coal. According to ThinkProgress, "already, more than one-third of American coal plants have been shuttered in the past six years, and the new carbon rules make it quite possible that no new coal plants will ever be built in the United States." “It was a very forward-thinking goal and truly remarkable achievement,” Aspen's Utilities & Environmental Initiatives Director David Hornbacher said. “This means we are powered by the forces of nature, predominately water and wind with a touch of solar and landfill gas. We’ve demonstrated that it is possible. Realistically, we hope we can inspire others to achieve these higher goals” Renewable energy has long since been on Aspen's agenda going back to the 1980s with the Reudi and Maroon Creek hydroelectric projects. Highlighting the accomplishment, former Project Coordinator Will Dolan said Aspen only began working toward its goal of 100 percent renewable energy about a decade ago. Beating Aspen to the 100 percent renewable landmark were Burlington, Vermont and Greensburg, Kansas.
Could evaporating water be the newest renewable energy source? Columbia researchers harnesses the power of bacterial spores
A biophysicist at Columbia University has discovered how to tap evaporating water as an electrical energy source using a simple device made from bacterial spores, glue, and LEGO bricks. Ozgur Sahin’s findings operate at the cellular level, based around his research on the Bacillus bacteria, a microorganism commonly found in soil—and its implications could potentially be far reaching. In high humidity, the spores absorb moisture from the air, expanding up to 40 percent in volume. In dry conditions, the reverse occurs. “Changing size this much is highly unusual for a material that is as rigid as wood or plastic, said Sahin, associate professor of Biological Sciences and Physics at Columbia University. “We figured that expanding and contracting spores can act like a muscle, pushing and pulling other objects. We noticed that we could harness the motion of spores and convert it to electrical energy.” Sahin’s prototype generator is modeled after a wind turbine, which captures kinetic energy and converts it into electricity. Attached to the generator is a flexible, elastic rubber sheet coated in a thin layer of spores. Using a fan and a small container of water, Sahin’s team showed that dry laboratory air and the evaporating moisture from the surface of the water can cause the entire sheet to curl up and straighten, rotating the turbine back and forth to yield electricity. “The biggest form of energy transfer in nature is evaporation. Our climate is powered by evaporating water from oceans and we have no direct way of accessing this energy,” Sahin pointed out. In a paper published in Nature Nanotechnology earlier this year, Sahin and his team, ExtremeBio, consisting of collaborators from Harvard University and the Loyola University Medical Center, showed that these spores produced a thousand times more force than human muscles, and that even a little moisture from evaporation could trigger movement strong enough to be harvested. “The subtle phenomenon of evaporation has big potential. This may be an opening for a completely new energy platform,” said Sahin, whose findings also bode the possibility of developing environmentally benign batteries and engineering stronger materials that mimic muscular movement in robots and prosthetic devices. Pound for pound, the spores pack more energy than other materials used in engineering for moving objects, according to Sahin’s paper. The ramifications are simply enormous in terms of energy savings for the construction and other industries, as well as possibly circumventing the depletion of fossil fuels. In an online issue of Nature Communications, Columbia University scientists reported the development of two novel devices powered entirely by evaporation – a floating, piston-driven engine dubbed the Moisture Mill, which generates electricity and causes a light to flash, and a rotary engine that drives a miniature car. Both devices contain a thin layer of spores. When the evaporation energy is scaled up, researchers predict that it could one day produce electricity from giant floating generators on bays or reservoirs, or from huge rotating machines like wind turbines that sit above water.
Plans emerge for the world’s first electricity-generating tidal lagoon—and it will cost a hefty $1.5 billion
UK developer Tidal Lagoon Power has lodged a proposal to create the world’s first electricity-generating tidal lagoon. Demanding a budget of over $1.5 billion, the Swansea Tidal Lagoon is slated to generate clean, renewable energy for 155,000 homes for up to 120 years. A tidal lagoon is a harbor-type structure that corrals a tidal sea area, and incorporates low-head bulb hydro turbines mounted within a concrete housing. Tidal movement over the turbines’ blades generates electricity—specifically, when gravity creates a difference between water levels on the inside and outside of the lagoon wall. Swansea Tidal Lagoon, master planned by LDA Design, has a nautical leisure aspect at its heart. The facility will include an oyster hatchery and restaurant and a water sport center, designed by FaulknerBrowns Architects, complemented with sports facilities, changing rooms and boat storage. Inspired by traditional fishing warehouses and boathouses, the 43,000-square-foot building will be constructed in conjunction with an eco-focused offshore visitor center, whose design takes after an oyster. The structure resembles a series of shells, with an internal area made from a range of overlapping forms that envelope interconnecting spaces which include an exhibition space, lecture theater, a café, and educational facilities. Designs for the visitor center were led by Juice Architects, working jointly with Evolve, LDA Design, Atkins Global and Costain. "Understandably much of the talk surrounding the Swansea Tidal Lagoon has centred around the energy-generating environmental issues. However, the most sustainable projects have both social as well as environmental benefits,” FaulknerBrowns partner Michael Hall told CLAD. “The same lagoon walls that will deliver a controlled predictable release of energy will also provide a safe sheltered environment for watersports including sailing and wind/kitesurfing. The scale of the enclosure has the added benefit of being an excellent spectator amphitheatre for sailing events,” Hall added. Located on Swansea Bay, the lagoon will benefit from the world’s second-highest tidal ranges of the Severn Estuary as a bountiful renewable energy source. The UK has made a legally-binding commitment to divert 15 percent of its energy use to renewable resources by 2020. Current figures stand at just five percent. If the Swansea Tidal Lagoon project is approved before the end of this year, it could be ready for operation by Q3/Q4 2018 and help the UK meet its goal.
Chicago's natural history museum, the Field Museum, announced Monday it has earned a Gold rating from the U.S. Green Building Council under the LEED for Existing Buildings Operations and Maintenance (EB O+M) program, becoming just the second museum in the nation to do so. (The Madison Children's Museum is the other.) Two of the museum's halls already achieved LEED certification separately, including its Conservation Hall, which is LEED Gold. But Monday's announcement marks a building-wide rating seldom seen for such building types—the hulking museum, made of limestone and Georgian marble, comprises nearly half a million square feet. Its 3D Theater is also certified under LEED for Interior Design & Construction. Greening a museum that dates back to the 1893 World’s Columbian Exposition was no simple task. (The current building opened in 1921, originally planned by Daniel Burnham and designed by his associate William Peirce Anderson.) In many places its neoclassical stone walls don't have an air gap with the interior brick and plaster, making it difficult to regulate the building's temperature. And, as was made clear when the museum applied for LEED certification, it doesn't function on a typical building's schedule. “A normal building might shut down at 5 [o'clock], but not for us,” said Ernst Pierre-Toussaint, the museum's director of facilities, planning and operations. More than 99 percent of the museum's collection is in storage, which has to be climate controlled and monitored constantly. Pierre-Toussaint said improving energy efficiency has been a goal for at least 15 years. Working with the Delta Institute—an environmental consultant that worked with the Field Museum on the project—Field Museum staff replaced about 30 percent of the building's 6,700 incandescent bulbs with LEDs, and installed 100 kilowatts of rooftop photovoltaic panels. Pierre-Toussaint said they hope to install up to 220 kW more—enough to offset 10 to 15 percent of the building's peak electricity demand —by 2025. The museum accounts for all of its natural gas consumption by purchasing renewable energy credits and carbon offsets. Much of the certification work came down to mechanical system logistics. The museum has 11 separate electric meters, and 13 for water use. Since some collections and accessible areas need to be heated—even during summer—while others are cooled, the museum installed demand-control ventilation to regulate air in sensitive exhibits individually. “We made huge strides over the past two years and are proud to share the results with our visitors,” said Richard Lariviere, the museum's president, in a press release. “One of the big challenges is planning long-term,” said the Delta Institute's Kevin Dick. “You can certainly make quick fixes. But you know an institution like this isn't going anywhere. So in 40 years what will this look like?”