Hurricane Sandy not only destroyed property but the power grid as well. Many businesses had to close due to a lack of power. Some had a generator system in place that restored at least part of their electric needs. But for the most part, Long Island and the New Jersey shore was in a state of black out for weeks to months.
Generators are possibly the number 1 item that is used for emergency
power that is used as part of a disaster recovery plan. Most stationary generators run on natural gas which is supplied by underground pipes. That is the same gas that is used to heat homes and provide cooking fuel. One of the big concerns with using natural gas is the delivery of the fuel. What if a large tree falls and the roots rip out the pipe somewhere along the line? It happens from time to time.
Some generators may have fuel stored in tanks on site like diesel, gasoline, propane and now some are using bio-fuel. But those are subjected to delivery problems if tankers cannot get through. Plus if not used the fuel can go stale or in the case of diesel, bacteria will grow in the fuel unless it is properly treated. Not to mention the fire hazard that these can be subject to like with gasoline.
Using green power can be a viable substitute for fossil fuels but that too has some drawbacks. I am going to run down the two most popular forms of green power fairly simply so you can have a better understanding of what is available.
Green Power is a name that is used for renewable energy that does not rely on fossil fuel. The three forms that are widely used to produce electricity are hydroelectric, solar and wind. Geothermal is another emerging method but is not really ready for the mainstream at this time.
Hydroelectric uses water to turn a turbine which in turn runs a generator. This has been used very successfully for many years long before the term Green Power came about. But it requires a dam to block a river to form a reservoir that supplies water to turn the turbines. This is out of reach for any small to large business and really is only feasible on a grand scale. Power companies have the resources to do this and as I indicated earlier have done so successfully for many years.
Next is solar power. This is clean, noise free and easy to install.
Solar panels are placed either on top of a building, over a parking lot or in a field where they can catch as much sun light as possible generally facing south in the United States. The panels can either heat water for domestic use and heating, or they can generate electricity through photovoltaic cells in the panels.
The panels that heat water contain an array of water tubes where water is circulated through either from street water pressure of by a circulator pump. The water in turn can be stored into an insulated tank until needed or pass through a heat exchanger that transfers the heat to another source of water.
The problem with solar is if there is no sunlight or limited sunlight where in that case the water would not be heated and there has to be some form of shut off to prevent heated water from being cooled as it is circulated back to the panels. For this a backup heating source might be required.
It is apparent that using solar for hot water can be best used to supplement existing systems. But in a disaster situation this maybe the only viable alternative provided that you still have electricity to run circulator pumps.
Another problem with using solar heat for hot water is no different than any other plumbing system and that is leaks can happen. The joints should be inspected routinely and if a leak is found or a fitting looks weak then a plumber needs to be called in. Thankfully leaks are few and far between.
Using solar for electrical power is possibly the most ideal use for it. Like in the example above panels are placed to catch as much sunlight as possible. Instead of heating tubes filled with water, photovoltaic cells in the panels convert the solar energy into electrical current.
The current the panels produce is known as Direct Current (DC) which is what your car, flashlight, or portable radio runs on. Since our offices all use AC or Alternating Current the DC power needs to be converted to AC through the use of an inverter. Inverters have been very popular in motorhomes and in some boats for many years. I even have a small one in my car that I use while traveling to keep my laptop charged.
When the sun goes down it is obvious that there is no power generation. To compensate for this during the day time the solar panels charge storage batteries like those that are in your car. These are connected to the inverter so during times of low or no sunlight you will still have electricity.
With the advances in solar cell technology even in low light conditions you can still get a fair amount of power generation. But since the sun is generally available solar makes an ideal solution for disaster power generation.
Aside from not having any or enough sunlight there are three additional drawbacks with solar power that need to be pointed out.
First is the service life of the batteries. Like those in a car you can expect three to five years of usage before they need to be replaced. This is because of the effects of acid in the batteries on the lead plates which hold the charge. The acid eats away at the lead eventually rendering the batteries useless in a few years.
Of course you will need a bank of batteries to give you any power for an extended period of time like overnight. The size of this bank is determined by how much usage you plan on having. Like in a small office you would not need too many batteries, but in a larger installation you could have a substantial battery bank.
As anyone who ever replaced the battery in their car can tell you that the battery can be very expensive. Depending on the amount of batteries and their sizes in the battery bank this could run into the thousands of dollars every three to five years.
The next big drawback of using solar is that when lead acid batteries are being charged or discharged through use they give off hydrogen gas. As we know from basic chemistry hydrogen is very explosive and needs to be handled carefully. We all remember what happened with the Hindenburg. So where the batteries are stored needs very good ventilation and if they are kept in the main building and not in a separate ‘shed’ designed for the batteries, you need to be sure that none of the hydrogen gas can get into other rooms. For the most part that is not too much of a problem. All is needed is careful planning.
The third draw back I will address later in this article which actually applies to any form of power system you select for DR.
The second form of green power is gaining popularity with major utility companies, especially those in the mid-west and western states is wind power. Using the wind is fairly simple and you need an area where the wind is blowing most if not all the time. In some areas there is very limited wind so using it for power is almost useless.
The government has produced wind maps of the country which can help you decide if wind power is for you.
The wind turbine as it is called produces D/C power just like with solar and this is used to run battery chargers and set up a bank of batteries for the times that there is no wind. And like with any battery system you will need an inverter or two to change the D/C to A/C for use.
D/C is not as efficient as A/C and long runs of cable can rob you of D/C power through resistance in the cable. Depending on where you plan on setting up the turbine you might have to have the inverter installed into the turbine directly. You may need to do this even with a solar system as well.
Before running out to have a wind turbine installed you will need to comply with various building regulations and in some areas the installation would be prohibited. You might need to apply for a variance and go through all kinds of legal headaches.
There has been some controversy over using wind turbines. First is the height of the tower to support the turbine which has to be at least 30’ above the tree tops and people can claim it as an eyesore and legal issues can crop up. Two types of towers can be used to support the turbine. One is self-supporting and those can be expensive. The next one is supported with guy wires from the tower to the ground. Room needs to be allocated for where the guy wires are anchored. So you just might not have the space. Next is the sound from the blades as they go through the air for it has been reported that the sound can be disturbing.
In very high winds like what is found in a tropical storm or hurricane can spin the blades so fast that they can explode, but this is very rare since the blades would turn in such a way to feather themselves as not to over spin.
A new issue that is cropping up is bird strikes. It has been felt that birds do not see the blades and can fly into them thereby getting killed. Animal rights activists could create other legal issues for you.
Regardless if you go with solar or wind power you need to plan how to wire the system into your building. You may have to have a disconnect that will isolate your green power from the grid. A long talk with an electrician and your utility company is definitely in order before you even buy the system.
As with anything there is a cost that needs to be considered and figured in. This brings about several questions. These questions will be pretty much the same regardless if you are deciding on green power or not. This is the third drawback that I mentioned earlier.
First, how mission critical is it not to have power and how long can you be without it?
The answer to this is by examining your business model. For some companies a few hours without power is all that they can tolerate while for other companies that would put a major strain on them and for others a few days or a week would be all they could tolerate. Here a long talk with your accountants is in order.
Next how much power are you going to need in a disaster? Again back to your business model. Are you looking to run everything or just certain functions of the company like clerical or executive offices? Of course one of the areas that should always be in the equation is your server / network infrastructure. Another area that needs to be in the equation is security for both fire and intrusion. If your security systems rely on telephone lines you need to be sure your telco system as power to cover those assets.
In the food industry refrigeration is always must to keep food fresh so that too needs to be figured in.
Most manufacturing plants most likely would not be able to take advantage of green power for disaster recovery, except the offices. Some warehouses could potentially use green power. I certainly would not expect to see a steel mill running on green power.
To determine your power requirement is relatively simple and requires only basic math.
Simply look at the labels on the equipment or owner’s manuals of the items you need to keep powered and find the wattage. Just add them together to determine how much power you are going to need while the main power lines are down. Mind you these figures are going to be for items turned on simultaneously.
Let’s say you determine that you need 8,000 watts or 8 Kw. You might be able to get away with an 8.5Kw power system but to be prudent and for a margin of safety a 10Kw system would be best. This way if something is turned on that you did not calculate for or if an item is drawing more than it should you will have a safety cushion.
What if wattage is not posted on the item or in the manual?
A lot of times amperage will be listed instead. Using the simple formula:
Amperage x Voltage = Wattage
You can determine the wattage of the device.
As an example you have a computer that draws or needs 5 amps or 5A. The standard electrical outlet in the United States provides 120 Volts or 120VAC. From here we can determine the wattage by plugging in ( bad pun ) the appropriate numbers.
5A x 120Vac = 600 watts
Now all we need to do is add that to all of our other wattages to determine what size power system we need.
From there it is time to shop around to see what is available. The prices will astonish you so be prepared for sticker shock. Although green power provides free electricity, the initial costs can be quite steep where you will need to question the return on investment or ROI. Again this will all depend on how much you stand to lose when the power goes out.
Let’s use my house as an example since I am currently working out of it. I live on Long Island where we pay some of the highest electric rates in the country. My average electric bill is $250 a month which obviously is $3,000 a year. I would need a 10Kw power system to keep my house operating. From here let’s look at Solar and Wind power.
Home Depot has a 10Kw solar power system for about $22,000 plus installation. Not adding in any finance charges it would take a little over nine years to pay off the system provided that it is being used to power my house all the time instead of emergency power which in that case it would take a lot longer to see any ROI.
Going to the Bergey website who manufactures wind turbines for home and businesses I came up with a price for a 10Kw wind turbine producing 220 Vac, a 100 foot tower and wire kit. The price for this not including installation, any options or legal fees was $50,180 which just increased the time for me to see a ROI significantly.
Has a home user it really does not pay for me to go green. But for a larger business it just might.
Depending on how much you stand to lose each day without power it might pay to install a green power system for disaster recovery and business continuity. This is where you need to sit down with your accountants, the utility company, your lawyers, your insurance company and if you lease your building, your landlord. Some utility companies may offer incentives to go green and you just might qualify for a tax break which could help offset the initial costs. After getting everyone’s take on the situation then you can decide to move forward with green power for DR or table the idea.
Even with the costs, the complexity and hassle of going green for DR could pay big dividends down the road in an emergency and keep your business afloat while others drown.
Photos – Generac