As we’ve previously discussed, the state of New York has set a target of going 100% carbon-free energy by 2040. But where does the state stand now, and what would it take to get there?

The Climate Leadership and Community Protection Act, passed in June, sets many goals including but not limited to procurement for generation of:

• Offshore wind projects: 9,000 MW by 2035 
• Distributed solar: 6,000 MW by 2025 
• Storage capacity: 3,000 MW by 2030 (1,500 MW by 2025)

The state has committed to investing $2.9 billion in 46 renewable energy projects. Just this summer it awarded two offshore wind contracts to generate about 1700 MW.

According to the EIA, as of 2018, 29% of New York’s in-state power generation already comes from renewable sources. The majority of renewable energy is generated by hydroelectric stations, then wind and the rest is from biomass, biogas and solar.

New York has put a lot of things in motion to help it move from 29%. Electricity generation is the area where the state has the best opportunity to make big strides. The New York Public Service Commission’s Clean Energy Standard (CES), has a target of 50% of the state’s electricity coming from renewables by 2030. It seems likely the state will achieve this, as the Nuclear Energy Institute reports that New York already generates 32% of its electricity from nuclear energy, which accounts for over half of the state’s carbon-free electricity. The state is also the third-largest producer of hydroelectricity in the country (number one east of the Rockies). 

A significant percentage (30%) of New York’s non-renewable energy use comes in the form of petroleum to power its public transit system. New Yorkers use public transit at a rate of five times the rest of the country. While this means that per capita, New Yorkers consume less petroleum than the rest of the country, the transportation sector reflects this use of mass transit. New York City’s Mass Transit Authority has committed to reducing greenhouse emissions by increasing the energy efficiency of their fleet and facilities. As the MTA goes green, so will the state and its fuel use.

The state has put together a Clean Energy Dashboard where you can follow along as utility companies and businesses work together to help reach this ambitious goal. According to the dashboard, which was last updated in July 2019, New York’s consumption and production is dominated by natural gas:

While the state energy companies are each working to make the move to renewable energy, the state is counting on businesses to do the same. The state and federal government both offer incentives to businesses to implement solar and wind energy systems. Many of these systems have been shown to pay for themselves within a decade, and thanks to the state’s net metering laws, businesses can sell excess electricity generated by renewable technologies back to the power grid. DOSE would be happy to consult with you to help be a part of this exciting transformation.

The use of a battery energy storage system (BESS) can prove to be quite beneficial as part of utilizing or distributing renewable energy such as from wind or solar systems. The BESS mainly consists of several batteries and rectifiers/inverters along with transformers and protective circuit devices. Batteries can be configured in modules of up to several megawatts, to be used in a variety of applications.

When energy is generated by wind or solar systems, it can be used many ways such as direct delivery to the load for consumption, delivery to the utility grid, delivery to an onsite storage system or a combination thereof. Clearly the latter presents a number of advantages as excess energy generated by the renewable system at times when winds are strong, the sun is bright, or power demand is low can be stored for later use, such as for moments when air flow is weak, at night time, or when power demand rises above average (usually at night time for residential properties). 

From the utility company standpoint, storing of renewable energy in batteries has the advantage of stabilizing grid power, as it can help cover peak load times, and thus increase reliability and extend capacity. It also increases predictability of energy flow, which is often required by regulations, and which some have criticized renewables for not providing in the past. From the consumer standpoint, storing energy in batteries has the advantage of helping reduce utility bills as the battery system can be used to complement energy generated by the renewable system as primary source of power to help meet peak load demand which are often times when utility cost/kwh is higher.

BESS and traditional power are not either/or options. BESS can complement and supplement other primary generation systems. Battery systems can respond to voltage spikes and sags. Battery power can be a great alternative to diesel-powered generators as uninterrupted power supply during power outages of other sources.

BESS can work with decentralized or central systems, and those that are on-grid or off-grid. This can be key for providing power in remote communities or facilities, which may currently be relying on diesel generators as they are far from the grid. 

Because BESS units may be placed close to the point of delivery, costs of transmission and delivery may be reduced, while reliability increases due to shorter distance of transmission and reduced likelihood of transmission loss. Another advantage of using  BESS is that there are practically no major local emissions to take into account in terms of affecting residents in the area.

There are of course several different kinds of commercial-scale batteries that can be used in a BESS. These include Zinc Bromine Flow (ZnBr), Lithium ion (Li-Ion), Sodium Sulfur (NaS),Metal-Air, and Lead-Acid. 

Valve-regulated lead-acid (VRLA) batteries are generally lower maintenance, do not spill or leak, and take up less room than legacy batteries due to their sealed construction, so they can be packaged tightly. VRLA reliability depends on several factors, including charge voltage, current and duration. But in general, you can expect a five-year life from them. A great majority of systems with power levels of up to 500 kVA use VRLA batteries.

Generally flooded cell batteries, sealed-cell batteries and flywheels are other top choices. Flooded cell batteries are the most reliable but also the most expensive. Flywheels can also be expensive but can be useful for certain space-critical requirements. However, they also have reliability and environmental concerns due to high rates of spin.

Some other considerations for choosing battery types:

• When lead-acid batteries are used, recycled lead (up to 99% secondary source) can be used. 
• Fluid pumps, which are required for flow batteries, will decrease overall efficiency by 3-4%, or more if there are additional cooling requirements. 
• Expected lifespan of lead-acid batteries is reduced by half with each 10º to 15ºF rise in temperature over recommended usage, of around 75ºF. VRLAs that overheat can dry out and experience open circuit failure. 
• At the end of a battery’s life, the potential of excretion of toxic metals into the environment must be taken into account and limited.

As energy storage also plays a role in electric vehicles and consumer electronics, new technologies are being researched and developed that should impact the productivity, efficiency and reliability of industrial batteries as well.

In our last blog, we discussed the Power Considerations of buildings with especially stringent needs for continuous power, specifically hospitals and financial institutions and their data centers. In this blog, we’ll look briefly at the unique heating, ventilation and air conditioning considerations of these industries.

Hospitals
Beyond needing to keep patients at temperatures that are comfortable for them, in hospitals a paramount consideration is of course doing everything possible to reduce the spread of bacteria. Sadly, old systems may be contaminated and spreading airborne contagions to those with the weakest immune system. Modern HVAC systems can reduce this risk. HEPA filtration systems, ventilation and recirculation systems, and targeted air flow systems can all help.

New technologies that involve static heating and cooling built into walls, ceilings and floors do not require forcing air through the building, cutting down on the potential for bacteria to move from one area of a hospital to another.

Other modern equipment can measure air quality, airflow, humidity, pressure, temperature and other factors, and then report and warn when these measurements exceed safe boundaries.

Financial Institutions

The ever-growing computation needs and server density at data centers means increased heat loads on equipment, and need for increased cooling. Hot spots can result in expensive and painful disruptions, so investing in new and superior air conditioning technology is money well spent.

The average data center uses more than 100 times as much energy as any other commercial facility of equivalent size. HVAC accounts for about one-third of the energy use. Some estimates say data centers could eventually use up to 20% of the world’s power supply.

But engineers are working hard to make sure that doesn’t come to pass. There are several technologies for reducing the power consumption of HVAC units in these data centers; and there are also techniques such as keeping aisles of servers separate from aisles that cooling fans draw from, and separating exhaust fans and AC vents. This reduces the energy needed by equipment to cool itself. The system can be enhanced further by situating exhaust fans attached to the building’s ventilation system within the hot aisles and air conditioning output vents in the cool aisles, again keeping these complementary services separate from each other.

And data centers do not have to stay as cool as in years past. ASHRAE has increased its recommended upper temperature from 77 degrees to 80.6 degrees.

But for data centers, HVAC is not just about temperature but humidity. Condensation can harm sensitive equipment, in worst case scenarios, shorting electrical circuits. But some humidity is needed to reduce the potential for damage from electrostatic charges. 45-55% humidity is considered ideal.

Installing an automated control system is another way to curtail the use of HVAC energy. The system can decide to switch off the artificial air conditioning and pull in air from the outside when cool enough. It can also monitor temperatures in multiple rooms to localize cooling or heating.

Taking these extra considerations into account will ensure that mission-critical environments are safe as well as efficient and pleasant to work in.

Overview of Power Considerations

Of course every business wants to have full power every day, but for certain sectors, power availability is non-negotiable. Data centers and equipment for hospitals and financial institutions fall into this category. In hospitals and the data centers that serve them, power outages are literally a matter of life and death, while at financial institutions downtime often feels that way.

Here’s a quick look at some key strategies to make sure these types of services are on track to meeting the ideal five nines (99.999%) reliability or uptime.

Uninterruptible Power Supply (UPS) + Standby Power Generators
Having standby power at the ready is the key to ensuring that there are no interruptions to mission critical power. The most reliable system is one that includes, besides the normal utility power, one or more generators, plus  batteries that provide uninterruptible power supply (UPS) for at least the moments of transition between utility power and generator power.

The first step to evaluating a generator system is of course figuring out the energy requirements of the system. Knowing ahead of time the full demand of the entire system, including the type of loads, is crucial to making sure the system will be able to perform as intended during those power outage events. 

Equally important is to decide on how long the system will be designed to operate at full capacity and what type of fuel will be used. This decision will need to factor in code requirements as well as owner’s aspirations and other considerations. For example in New York City, code requires the generator system be provided with “fuel supply sufficient for not less than 6-hour full-demand operation of the system.” However, it is common for generator systems to be designed with fuel supply for a period of well over 24 hours to supply mission critical loads in case of extended power outages.

The start-up power requirements of the generator system will affect unit selection. A major factor in this calculation includes voltage drops at startup which can be significant since this is the point when major motor loads draw the most current (in-rush current). For larger loads, a set of generators may be the best solution, allowing for a staggered start of motors. Again, regulations may dictate the maximum delay in starting times and standby loads.

On the other hand, purchasing an oversized generator adds to the cost of the system and may actually decrease efficiency and reliability, as many generators are not meant to operate at less than 30% of their rated load. Purchasing a system that allows for a steady ramp-up of power, or “walk-in” helps mitigate the chances of loss of power during the transition to generator power, as it reduces the frequency and voltage fluctuations on the generator output.

Another important factor to consider is total harmonic distortion (THD) which can cause the generator to overheat, and create voltage distortion in the system. It is possible to buy a filter to reduce THD, but it’s important to get the right one to avoid the potential for UPS to fail to pick up the load from the generator power. Your UPS and generator must be compatible: the UPS must accept the range of fluctuations in voltage and frequency that will naturally occur when using generator power. If they are not a good match, power will continue to be drawn from the UPS to the load rather than from the generator during a power outage, leading to the danger of depleting the batteries.

To avoid this, an on-line UPS will convert incoming AC power continuously into filtered DC power, and reconvert it back into AC power with a pure sine wave. This will be music to the ears of your sensitive electronic equipment.

Now what if your generator or UPS coincidentally fails to function during one of those power outages events? This brings us to the concept of redundancy. Depending of the business owner’s investment capability, systems can be designed to address such scenarios. For example, one extra standby generator (or UPS) can be provided, similarly sized with the required system and installed in parallel with said system. This is known as N+1 system configuration and provides greater reliability than the basic system.  

Hospitals

For some hospitals, replacing older electrical infrastructure needs to be a priority. The good news is that replacing equipment means less frequent repairs, lower utility costs, increased reliability and safety, reduction and automation of several aspects of maintenance, and often some regained square footage. All of which means fewer headaches for administrators. Investing in modern technology will have a positive impact on both employees and patients.

Financial Institutions

The data needs of financial institutions are vast and vital. Information must flow quickly, without any interruptions. Even a few minutes of downtime during stock market hours could mean the loss of data tracking and action worth millions of dollars. Designing for redundancy and resilience is the key for peace of mind.  Ongoing, diligent maintenance of all aspects of the power system is crucial.

In short, there are many details complex in nature to keep in mind when designing mechanical, and electrical systems for mission-critical facilities. Be sure to consult with a professional engineer such as at DOSE Engineering or other experienced professionals as you look at your options.

Read Part II: HVAC Considerations