Enter your email:

Construction Topics




















Become a FB fan

Construction Network

Trades Hub


January 23, 2010

The Explosion of Wind Energy
Filed under: Energy — Tags: — nedpelger

I’m positive that you have nothing in the next 18 seconds that will bring you more joy than watching this video.


Try not to build like that or live like that.


January 1, 2010

How Does Energy Differ from Power?
Filed under: Energy — Tags: — nedpelger

Whenever I hear someone on the jobsite using the wrong units (they say pounds of air pressure when they mean psi or they say BTUs when they mean BTUs/hour or BTUs/sec), I think two things. One, they don’t really understand what they are talking about. Two, they will be making some mistakes due to that misunderstanding that could be easily avoided. Pet Peeve alert! Learn and use the correct units. It will make you look smarter and save you some aggravation.

So how does energy differ from power? Energy is the ability to do work. 1 BTU heats 1 pound of water 1 degree Fahrenheit. It takes energy to drive your car, heat your house, or charge your battery. Another example: 1 KiloWatt-hour of energy lights a 100 Watt bulb for 10 hours.

I think of power, on the other hand, as capacity. Power is the rate at which energy is used. BTUs/hour, Horsepower and KiloWatts are are units of power. That light bulb has the capacity to use 100 Watts, it’s level of power is 100 Watts. The Formula One race car has the capacity of delivering 1000 HP, while a Ford Pinto powers along at 88 HP. The Formula One race car can use energy faster than the Ford Pinto (unless the Pinto is exploding from a rear collision, then that’s a different calculation).

So let’s do a quick calculation to compare the gasoline usage of the Formula One vehicle and the Pinto. We can easily find that gasoline has an energy value of 125,000 BTUs.

So the energy is in the gasoline (and yes, I know a Formula One doesn’t run on gasoline), but the power is the capacity either vehicle has to use that energy over time. When trying to remember the units, the little graphic above about power (having a W) and watts is helpful.

Since I’m working on some solar energy projects, let’s try an example from that field. The sun’s energy on a given surface is called the irradiance. So that’s the energy portion. The power portion is radiation. The radiation is the irradiance measured over time (just like power is energy measured over time). Solar radiation data is measured in KiloWatt-hours per square meter per day. From solar radiation charts, we find a horizontal plane in Harrisburg PA in March gets an average of 3.3 KiloWatt-hours per square meter per day.

To recap, the most common energy units are BTUs, KiloWatt-hours while the power units are BTUs/hour, Horsepower and KiloWatts. The rest of the conversion units are also available on this site.

This post will be included in the database.


December 30, 2009

Green Opportunities
Filed under: Energy — Tags: — nedpelger

That big splash you just heard was all the almost-out-of-work contractors  jumping into the pool of green construction. An article in ENR today noted that Orlando Electric Utility is bidding a 10 MegaWatt solar project and has 27 teams of bidders. That amount of interest surprised everyone. A similar request for proposals last year netted 10 bidders.

Several years ago OEU put photovoltaic solar panels on the roof of the Orlando Convention Center at a cost of $7M and production of about 1 MegaWatt. They must be pleased with the PV solar performance to be returning to the table for a much bigger helping.

The article further noted that FPL (Florida’s biggest utility) is also planning some PV solar projects. Though the fact that they stated they can produce electricity for $0.12/kwhr with coal and $0.26/kwhr with PV solar made me wonder.

I’ve recently had several customers ask me about ways to use green solutions to help the environment and save costs. That’s the kind of problem I enjoy solving. An electrical contractor and friend also started pushing that side of his business. This combination of trying to do good and do well appeals to me.

I’m working on several large (1 MegaWatt to 16 MegaWatt)  PV solar projects and having great fun with them. I love figuring out the most efficient ways to build and maintain things, so I’m like the proverbial pig in poop. The photo below shows a similar project at The Solar Grove® at Centocor Headquarters in Horsham, PA (a Johnson & Johnson company).

If you find yourself with some available time, learn about the various green technologies. Just go to Google and start searching and reading. Remember, your value in the market depends much more on what you do than what the market does.


October 21, 2008

Puerto Rico to Produce 20% of Electricity by Wind
Filed under: Energy — Tags: — nedpelger

The island of Puerto Rico, with those steady breezes, now pays almost $0.28 per kilowatt-hour for the energy generated by gas turbines. The state-owned Electric Energy Authority decided to invest in 20 wind turbines in hopes of generating electricity they can sell for $0.09 per kilowatt-hour. The project budget is $160,000,000 and slated completion is 2015. The photo below shows a New Zealand project.

The spiked energy prices of the last year will create lots of opportunities in the near future. I think biofuels (switchgrass, poplar trees, etc) converted to ethanol may be one of the big winners, but they still have a couple of chemical engineering challenges to solve at the large scale factory level. Corn ethanol has always been and will remain dead on arrival. It’s a terrible idea to tie food and energy together.

Who knows if the world is really ready to start permitting the construction of nuclear reactors again, but I doubt it in this NIMB (not in my backyard) world. Certainly America will have to have significantly harder economic times for that big of a shift in mindset.

The one rising star in the energy field will certainly be wind power. It won’t ever be a primary world source of energy, but in certain regions it will absolutely be significant. So way to go Puerto Rico, you did good!

« Newer Posts