There’s growing interest in designing energy- and cost-efficient structures.
By Carol Brzozowski
The interest cuts across all sectors: commercial, industrial, residential, and municipal.
Albert Thumann, executive director for the Association of Energy Engineers, describes energy audits as “basic tools to evaluate a facility’s energy usage and losses and determine the economics for making energy conservation opportunity expenditures.”
Not all audits are the same. “The more money you put into the audit, the more opportunities you will find,” says Thumann. “Most companies do a walk-through to find the low-hanging fruit. These don’t require much capital expenditure or operation maintenance. It’s a physical inspection on how a facility is performing.”
The next level is a “mini” audit, involving facility tests and measurements. For example, a lighting audit would entail using a foot-candle meter; a combustion analyzer is used for a combustion audit. That audit identifies opportunities and economics for changes.
“An opportunity may be to replace the lighting with compact fluorescents, and it’s going to cost ‘X’ amount of dollars and give a return of ‘X’ amount,” says Thumann.
The highest level is called the maxi audit or investment grade audit. “In this type of audit, you simulate the building facility and how it’s going to operate on a year-long basis,” says Thumann. “It’s going to perform differently in the winter or summer based on the ambient outside temperature.”
This audit type uses a simulation-type modeling program to evaluate how the facility will act year-round. An accounting system offers the building owner a picture of how many square feet is dedicated to each segment of energy use.
An energy and a water audit should be conducted every four years, Thumann says. “It’s an ongoing process. You’ve analyzed if there’s any waste going on and the way you get billed. It’s a complete evaluation.”
Thumann notes a surge in audits that he says is driven by a variety of dynamic forces. “From a corporate and government perspective, there are more driving forces for energy audits today than ever before,” he says. “There are many provisions in the American Reinvestment and Recovery Act [ARRA] that require audits of federal buildings. There’s a movement for green building by the US Green Building Council, as part of the LEED [Leadership in Energy and Environmental Design] for existing buildings.”
There are companies that have set goals to reduce their carbon footprint, Thumann adds. “You then have to manage energy more effectively; that’s where the energy audit comes in. There are also the political aspects of global climate change with cap and trade and reducing carbon emissions.”
Also, there are more incentives, such as grants offered by the US Department of Energy and rebate programs from local utilities.
For the past five years, the Association of Energy Engineers has offered certified auditor training programs for commercial buildings and homes. The programs also include a mechanism for testing and evaluation of how well a professional performs in the industry.
The Association of Energy Engineers maintains a list of more than 15,000 people who have been certified through its program. In addition to training and examinations, credentials and previous experience is verified.
Those interested in certification, finding a certified energy engineer, or learning more in general about the industry can visit the organization’s Web site at www.aeecenter.org.
Energy conservation is one of the most basic forms of distributed energy. The most efficient way to conserve is to correctly identify problems areas that, with corrective measures, can produce positive results. And what others see challenging economic times for commercial and residential developments and projects, Brian Johnson, of Applied Energy Solutions in Traverse City, MI, sees opportunity.
“I think we’re in very exciting times,” he says. “The country’s in a funk right now because we’re changing. The industrial revolution was a boon to us, and now I believe we’re in a new technological evolution.
“There is an actual energy economy that is going to come to fruition in geothermal, wind, and solar,” says Johnson who, along with Paul Barron, owns Applied Energy Solutions. “They’re even talking about a new air-to-air heat pump that works in conjunction with photovoltaic.”
The potential for making America’s buildings more energy efficient is extensive, Johnson points out. “We’ve got 200 years of structures to fix, and it’s a substantial fix,” he says.
Johnson says a homeowner may erroneously believe spending $20,000 on windows with a payback of 50 years will solve their energy efficiency problems. “That’s where the audit comes in best,” he says. “With $3,000 worth of sealing and insulation and making sure their furnace filters are clean, it could be two to three years to payback, depending on the dollars it takes to fix it. We try to get them paid back under five years.”
Johnson notes it’s the first time in the country where private dollars—instead of public—are used to fund energy efficiency efforts. Interested clients complete an online form. A BLISS representative ensures the client qualifies for a loan, and the credit union determines the client’s ability to pay back the loan. If the client meets the criteria, a qualified energy audit company conducts the audit.
Through the audits, Johnson says he and Barron have found that builders—through no fault of their own—weren’t concerned about how to build an efficient structure. “They went cheap on insulation, the ceiling and the holes through the rim, and band joists, and everything you can’t see,” he adds. “What we’re faced with now is going into the structures and finding where they went cheap.”
A typical audit includes taking measurements and photographs of the building’s exterior, including windows and overhangs; looking for shade, such as trees; examining the building’s position, the condition, and the siding. After checking for problems with the exterior, the men go inside and turn on fans and dryers—anything that is exhausting air to the outside.
One of the diagnostic tools his company uses is a blower door, a powerful fan that draws air out of a building, lowering the air pressure inside. The higher outside air pressure flows in through unsealed openings. The team calculates cubic feet per minute coming into the building and the number of air changes per hour, formulated according to national standards. Johnson and Barron also use an infrared camera to detect temperature changes to look for where air is escaping.
Aside from using technology to detect problems, the team advises simple modifications that can save energy and money, such as switching to compact fluorescents, which uses less energy, but offers the same amount of lumens. In another example, motor efficiency has gone “through the roof” in the past 10 years with upgrades saving energy, Johnson says.
“Air-conditioning units have become more efficient,” he adds. “The different sources of heating we’re now looking at are solar water and geothermal—they are the most efficient systems there are. High-efficiency furnaces are condensing furnaces. With the gas escaping through the flue, they’ve figured out if they can attract that and push it through the condensing part in the furnace, they can get the heat out of the flue and up to 97% efficiency for your dollar.”
WaterFurnace geothermal units can use 50-degree water to expand the gas in the furnace to make heat, making it 300% efficient, says Johnson. “It’s an expensive system to install, but once you spend the dollar for the energy, you get three dollars back worth of heat,” he says. “It’s like anything—you buy the best system, and you get a better return down the road. It just takes a little longer to pay it off.”
The biggest energy waster is either poor insulation or at the rim and band joists, Johnson says. The goal is to get a building to be more efficient, but not too “tight,” notes Johnson. “Back in the 1970s, they were sealing buildings up until there was no air infiltration, and you do need fresh air.”
Energy conservation is onsite energy production, adds Johnson. “Once you get your house efficient and control your energy use, then you’re conserving natural resources and producing less carbon.”
The biggest challenge in conducting energy audits is educating consumers that what they can’t see is costing them, he says. “What’s going to be a bigger challenge is when the temperatures get to 50 to 70 degrees, their power bill goes down, and they stop thinking about it. It’s hard to get them to think about the next 10 winters.
“We’re pushing comfort: Why are you going to freeze for the next six months out of the year when you can be comfortable and it won’t cost you anything more?” continues Johnson. “You can actually start saving money.”
One company that operates in the commercial sector is Comfort Systems USA Energy Services. The company provides mechanical systems installations and other services nationwide. Comfort Systems USA Energy Services’ audits are higher-level onsite audits typically done on more complex systems, says Brewster Earle, president. Less complex systems can usually be analyzed at no cost by utility companies, he adds.
“There is a lot of opportunity when we can consult with our clients—whether it’s building retrofits or new buildings—to look at the energy efficiency and sustainable options,” says Earle. “Our primary mission is to work with local operating companies to add value to their typical delivery methods. We focus not only on the mechanical pieces of the building, but on the whole building, and the way it is using energy or will be using energy after construction.”
Each audit is done case by case to determine priority issues and opportunities. “We do preliminary calculations to ascertain what is being done, how much is it costing to operate the different systems, and if there are opportunities to reduce the costs,” he says.
The company reviews the client’s annual utility spending, reviews the systems in place, and interviews building operators to understand how the building’s different areas are being used, the run hours expected on the equipment, and how equipment is controlled and operated. Then, the company goes onsite to do a final system evaluation, including analyzing existing building control systems to determine if there is a disconnect between what the operators say is going on and what is actually going on, Earle says.
Oftentimes, customer service requirements dictate how a system operates, he points out.
Case in point: A hospital, where the comfort of patients as well as the nursing staff often drives the temperature at which systems are set—and the temperatures may vary on individual floors, Earle says.
Schools are another example where there may be varying requests for set temperatures, he adds. “Even in a commercial environment, there are constant complaints from the tenants, and the natural tendency is to accommodate those folks to minimize the complaints. That often means you’re going to be exercising the systems outside of what might be more efficient.”
There may be times when the sun may be beating down on one side of a building, and on the other side people are cold. “If the systems aren’t designed to accommodate that differential, you’re going to have constant problems,” says Earle. “If you know you have some of these dynamic nuance complexities and all you’re looking at is a very plain, unoriginal software program to do your audit—what kind of lights do they have, what kind of systems do they have—to me, it’s just checking boxes as opposed to really tying to understand what’s going on in the building from the operator’s and occupant’s perspective.
“On our site audit, we’re consolidating all of this information to get a good handle on how the system is actually being operated and validate and verify what is in place and how it’s performing,” he adds.
Depending on the level of audit being conducted, that could mean doing data logging or putting in meters or sensors to verify that the chiller’s performing at a certain level. “Sometimes we can get that off of an existing control system so we don’t have to go to that level,” says Earle.
After identifying the priority list, the next step is to determine costs associated with retrofitting or impacting the systems “to change them for the good and to lower the operating costs,” he points out, adding that, while some measures may at first look like good opportunities, they may be eliminated from a cost-benefit perspective as priorities develop.
The fundamental first audit is followed by a client consultation to determine what changes are operationally feasible, which require immediate focus, and those that may require another site visit to further understand and validate the impact of that change on the building’s operation.
Comfort Systems USA Energy Services works toward a 100% cost certainty, because the company makes a proposal to do the work as the final step in the process to validate the savings opportunity and nail down actual costs associated in achieving the savings.
“At the end of the day, the entire process results in a financial decision tool put together in the language of the particular client we’re working with, which is the ultimate goal,” says Earle. “Each company has a different matrix it uses to assess different returns on investment for their own business.”
One of the biggest opportunities in saving energy comes in turning off that which is not being used, Earle notes. Another key action is to match the system to the use of the space, he says.
“When we’re doing audits on an existing building, we find that systems were designed to serve a specific space for a specific use, and that has changed over time,” he explains. There are times we can get efficiency gains in getting the system to operate as it was designed to operate.”
For example, it is typical, in the construction of schools or other buildings relying on complex systems, that the builder does not adequately explain to the operators how the systems should work. “Their priority is to get it built as quickly as they can and move on to the next job where they’re going to make some money,” says Earle. “That is the fundamental issue at play where we see opportunities when we go into these building audits.
“A few years after the owner has that building, we’re almost certain that building is not going to be operating as it was designed to operate,” adds Earle. “That’s where we assess how the building was designed to operate, and where can we find efficiencies.”
The audit process is linked with a recommissioning process. “We very strongly urge the client to consider this an ‘energy audit on steroids’ and look at the opportunity to recommission the systems to operate as they were designed to operate,” he says.
Part of an energy analysis also includes water efficiency. Earle points out that by using less water in many systems, “You’re not pumping the same amount of water, so you’re not using as much energy to deliver that water.
“Our mission is to help the client understand the options relative to sustainable building practices or high-efficiency systems,” he continues.
Energy audits do not do much more than provide information, Earle says, adding that if he had a nickel for every energy audit that was performed where there had been no follow-through, he’d have a good sum of money. Others who perform audits concur.
“When folks are buying an energy audit, the application is very important,” he says. “What do you want to do with it? Having an energy audit gives the building owner the opportunity to establish how they are consuming energy systems in the building.
“The fundamental premise of doing an audit is finding out how to help the client save money and reduce building costs by making the systems more efficient. That helps the client understand a continuum of choices from the very simple to the very complex, and on that continuum, price is relative from capital spending to no spending.”
Earle says one of the biggest challenges in energy efficiency is that it is not often on the radar for companies. “People are focused on their product or service. Up until a half-dozen years ago, energy costs were a fairly small percentage of their business, and it was not in the line of sight for the economic drivers of the business.
“That was often delegated to folks like a facility engineer or manager; it wasn’t a conversation in the board room,” adds Earle. “For a private business, it’s been off the radar, and now it’s being foisted on folks, and it’s outside of an area of expertise. Consequently, there’s that education hurdle you have to overcome so people feel comfortable making significant decisions about areas that are slightly outside of their expertise.”
On the other hand, Earle says, “We’re seeing a lot of businesses that have hired people who have specific expertise—that’s great because we love working with an educated customer.”
Two questions clients usually have are: How much is the company going to save, and what is it going to cost to save that? “It’s easy to say how much it’s going to cost—nobody’s going to challenge that—but what people can challenge is the savings side of the equation,” he answers. “How do we overcome that?
“We encourage people we work with to have an independent party check our calculations if there are any doubts,” adds Earle. “In order to secure a lot of these utility incentives we just talked about, independent third parties evaluate our calculations for accuracy.”
There also can be a challenge in the municipal sector, particularly with school boards whose members make financial decisions, but lack the expertise to address energy efficiency issues, he notes. To finance energy efficiency initiatives, there are a number of incentives available.
“There is a plethora of incentives available from the US government in the form of grants, tax credits, or deductions—we have never seen so much in the history of America,” says Earle. “Then there also is a ton of local and state utility incentives to do the same. The local utility doesn’t want to have to build more generation, so they’re going to put the money toward incentivizing people to use less energy on the electric side of the business.”
Demand response programs enable utility customers to contribute energy to the grid during peak times by reducing non-essential power usage. Hess is a demand response provider in three programs: the Pennsylvania, Jersey, Maryland Power Pool (PJM)’s Regional Transmission Organization (RTO); the New York Independent System Operator (NYISO); and ISO New England.
“We provide demand response as a value-added service to our customers to reduce their energy usage,” says John McDermott, manager of energy engineering.
Audits are done at no cost to the customer and include advanced metering equipment and access to Hess’ online energy monitoring system, the Hess PowerPort platform.
Hess engineers determine whether clients are a good prospect for the program through an initial screening. When Hess conducts an audit, company engineers visit the client’s facility to meet with that facility’s engineering group to get an understanding of how the facility operates and when energy is being used.
“We identify if they have any power generation onsite, whether they’re strictly a commercial or industrial facility, and what opportunities there might be to either completely shut down operations or switch operations to a different time of day, or start a generation unit at the time of a peak load,” says McDermott.
“Prior to going to the site, we obtain the facility’s interval data to get a good idea of what their profile looks like so we know what their usage is during off-peak hours versus on-peak, weekends versus daytime, and daytime versus nighttime,” he adds. “We go through a series of questions with their engineering group to get a better feeling for which equipment is operating during those times we see higher consumption. Then we get a feel from them as to what it is that is not essential that we could shut down during periods of time—except for those times you are called on by the ISO under an emergency condition where we’re trying to avoid a black-out or a brown-out.”
Energy needs are grouped from critical to non-essential, allowing a priority to be established should the need arise to shut those sectors down during high peak usage. Such items include lighting, air-conditioning, and various motors on a production line. After that process is completed, Hess evaluates the data to create a detailed report of what steps the client can take.
In some cases, Hess engineers find that even in times of low production, energy use is high. “They may find out their air-conditioner temperatures are set too high in certain places, or they are leaving lights on in a warehouse and can shut those off,” says McDermott. “They can considerably reduce their consumption during those off-peak hours, so it helps them in another ways outside of the demand response effort.”
In one such project, Hess provided demand response services at the 7,800-square-foot facility of Tabloid Graphic Services, in Pennsauken, NJ. Hess’ Energy Marketing division pays Tabloid Graphic Services monthly to commit to reducing electricity usage during peak demand times when local power grids are under significant stress and the power grid operator requests a short-term reduction in energy consumption. As a result, Tabloid Graphic Services identified 400 kW of curtailable power in its facility to make available to the local power grid if needed—enough to power 300 New Jersey homes.
The company commits to shutting down printing presses and air conditioners. If the company is called upon to curtail power, it receives an additional payment from Hess. Sometimes energy savings comes down to something as simple as turning off unused machinery, McDermott notes. “Whether it’s force of habit or standard operating procedures, they leave it on over the weekend or overnight, when it really doesn’t need to be on,” he says.
Demand response programs are catching on, McDermott says. “People are looking for more opportunities to reduce their energy expense, and this is one way they can do it.”
Like most cities throughout the US, Dayton, OH, city officials took note of its aging infrastructure and sought greater efficiencies as components of its system were being replaced. And like most municipalities, city officials sought to get “bang for the buck” when doing those replacements, notes Donna Winchester, environmental manager for Dayton. “We knew we had a lot of work that needed to be done,” she notes.
Yet, “You don’t know where you are going unless you know where you are,” she says, adding that energy audits help to bring the picture into focus. “You need to look at what you need to do to improve. Some things are simple, and some more complex. A performance-based contract is the way to go. You see your savings; you spend your money accordingly.
“All cities are looking at more visible projects, such as solar and wind,” says Winchester. “If you look internally at your own buildings, you can have tremendous savings.”
Dayton has a $3.2 million energy conservation and building modernization program contract with Honeywell. Honeywell’s program helps Dayton meet goals in its sustainable practices policy and commitments associated with the US Conference of Mayors Climate Protection Agreement. The actions on the plan included chiller replacement; lighting upgrades; switching out some traffic signals to LED; replacing boilers; working on building envelopes; upgrading energy system management, heating, and cooling at the city garage; and lighting retrofits. Honeywell’s contract also included audits and improvements to earn the Energy Star seal of approval for City Hall.
Dayton expects to get a payback of about $420,000 a year in savings in 2009 dollars for following Honeywell’s plan. The plan is expected to show a 30% decrease in utility expenses and greenhouse gas emissions. The program is funded through a 10-year performance contract, with monies coming from the general fund.
“Honeywell was right that the savings are going to pay for this,” says Winchester, pointing to the rising cost of utilities. “Unfortunately, it’s not going into another pot to fund other things. We won’t see much dollar savings, but we will see the kilowatt savings. The money will help us continue our operations.”
The upgrades are expected to reduce electricity consumption by an estimated 3.7 million kWh per year and decrease carbon dioxide emissions by nearly 4,000 tons each year. The modernization is being funded from the general fund.
One of the most effective energy-saving measures is lighting change-outs, Winchester notes. “The best dollar you spend on energy is a dollar you don’t have to spend,” she says. “Some things cost a lot of money to install. You have to look at the benefits and payback time. Lighting is simple and has a very quick payback. I would recommend to anyone: definitely look at your lighting.”
In addressing energy efficiency in a building, typical challenges focus on trying to please everyone who works together in the same building, says Winchester. She credits Honeywell for an “excellent job,” but, just like any kind of heating or cooling control in a building, “you have one person who’s warmer than the next, and that’s always a challenge. Even with the best system, it’s still a challenge.”
Dayton residents are supportive of the program, Winchester says. “It’s got a payback, and with the cost benefit analysis, it shows this is something that benefits the city in the long run.”
Energy audits are all about economics, asserts Tim Michels, president of Energy Solutions in St. Louis, MO. “We help people save energy in buildings so they save a lot of money,” says Michels. “As much as I do this out of my passion for the environment and energy, it’s really economics. If it doesn’t make sense, it doesn’t make sense. The real problem in this country is that most people don’t realize how much sense it does make.”
But city officials in St. Louis have realized that. They chose Energy Solutions to conduct a two-phase comprehensive energy master plan, including an energy audit of city hall and the Carnahan Courts building, comprising approximately 850,000 square feet, to help the city develop an energy conservation strategy to apply for $3.7 million in block grant funds from the US Department of Energy. That phase was completed in October.
The second phase entails an energy audit and analysis of six additional city buildings, comprising approximately 1.2 million square feet. The two phases will analyze more than 50% of all of the city’s buildings.
After examining lighting, heating, and cooling systems, Energy Solutions came up with 10 specific items in each building, Michels says. “Some of them are mutually exclusive, meaning if you take this path, you can’t do that, so there’s a net of eight actions that could be done in any one building,” says Michels.
In one building, the company identified measures that would enable the city to save 30% of energy consumption with paybacks between seven to 10 years, Michels says.
St. Louis will be using federal stimulus money to work on some components of the audit recommendations, with the second phase expected to start when the Department of Energy approves the funding, which comes from ARRA. Those recommendations include improving building controls and controlling outdoor air when it’s not needed.
“You don’t want to heat and cool all of that outdoor air that the ventilation system is bringing in if people in the building don’t need it,” points out Michels. “The three major things that get the highest yield are lighting, controls, and some modification of how they were pumping their chilled water around.”
Michels finds there is more of a challenge in doing audits for the private sector. “We penetrate the institutional sector quite easily and well,” he says. “They’re more interested in this. The private sector has two major problems with its perception of what they’re dealing with. The first one is the mantra that it has to pay back in 18 months.
“That makes sense if you’re doing a new product line that may have limited life in the market, but when we’re talking about boilers and furnaces that are going to have a 20-year life and are going to be there regardless of what the production line is, it would seem to me that if I could demonstrate for you a payback, you would be willing to do something about it,” he continues. “That’s a 25% return on investment. I’m not sure they’re getting that out of anything else they’re doing.
“It’s important the facility owners understand that by creating energy efficiencies today, there will be a positive long-term effect—perhaps not in 18 months, but surely in ensuing years,” says Michels. “You’re going to have to replace this piece of equipment anyway. You would replace it if it failed. Let me replace it with something that’s very energy-efficient relative to the other things that you’re doing.
“They’re not willing to take that step to think about replacing it, and then, when it does fail, they don’t have time to think about it,” he says. “They haven’t done the master plan ahead of time to know what they should do if and when it fails before they need to.”
Another challenge comes when energy costs are lower on a company budget, compared to other big-ticket items, such as labor costs. “If you’re talking about an office building, energy may be 3 to 4% of its total operating costs, but it’s really the salaries that take the most money, so the problem we’ve got is society seeking to make the savings occur where they can see the biggest numbers. Energy falls off the table almost, when it’s compared to things like that,” says Michels.
Energy Solutions’ audit discovered the typical energy waster in St. Louis is that many of the buildings could use significant recommissioning. “They were probably built with equipment that was much larger than needed for the load,” notes Michels. “That equipment generally will operate inefficiently. A lot of it is probably at life cycle. Sometimes the loads are smaller because since the 1970s, they may have put in all new windows. The heating and cooling load may be significantly less.”
The same is true for lighting retrofits, Michels says. “You replace incandescent lights with fluorescent lights and are using one-fourth the energy, or you’re now needing one-fourth less cooling to remove the excess heat of the same amount of lighting,” he says. “Right-sizing of the equipment is a good first step if the equipment needs replacing. As you do that, make sure you put in the most efficient equipment.”
One of the most substantive changes building owners can make going forward is choosing frictionless chiller technologies, which are more efficient than existing cooling equipment, Michels says. With heating, modular condensing boilers are the way to go, he adds. Many older boilers were initially oversized, yielding a range of seasonal efficiencies of 60 to 65%. The newer equipment runs 90% efficiencies.
“By just changing the plant, you save energy and get quick paybacks,” he says. “Many times, they’ll switch the technology and do boiler improvements at the same time. By making a steam-to-hot water change for heating, we can almost guarantee a 30% utility bill for natural gas. Steam is less efficient than hot water.”
Equipment could be fighting itself and compromising energy efficiency, says Michels. “There are many buildings operating with a variable air volume and terminal reheat system, so it’s cooling and reheating at the same time,” he says. “Recommissioning rebalances it, making it more efficient, so there’s a minimum amount of sub-cooling that then needs reheating.”
For lighting, Michels favors lumen maintenance ballast, which offers better control of light levels, including taking advantage of automatic daylighting.
“If the sun is out and it’s shining in, it will actually almost turn the lights off, because the daylight is now providing the 40-foot candles,” he says. “It’s working all of the time on a performance basis to make sure you’re getting the light you asked for. And if you’re getting it, it turns itself off. That’s a new ballast technology we’re putting in, in as many places as we can.”
Energy recovery on exhaust systems can save 50% of the energy required for ventilation, Michels says. He points out that the pendulum has swung from the 1970s, in terms of energy efficiency. “One of the reasons why we tightened things up in the 1970s is because bringing in outdoor air was not always better quality than the indoor air,” he says. “Now you get extra points for overventilation. The assumption is if we’re purging a building, we’re getting rid of all of the bad pollutants.”
Michels says he does not like to represent to clients that energy audits will solve their budgetary problems. “When you’re looking at a school that has a $25 million annual budget, and energy is $1 million of that, even if I cut the energy costs in half, it works to help, but I’ve only saved $500,000.”
However, “If this country is really serious about solving its energy crisis, we have to be convincing people it’s a very cost-effective thing,” he adds. “We’ve got to save it before we make it from renewables. Although I’m very high on renewables, they are a lot more capital-intensive than energy efficiency. I don’t want to make photovoltaic electricity to waste it in incandescent lights. I’d need one-fourth of the photovoltaics that you’d have to buy to put in if I change that technology to some new fluorescent or LED technology.”
Author's bio: Carol Brzozowski writes on the topics of technology and industry.