Showing posts with label energy consumption. Show all posts
Showing posts with label energy consumption. Show all posts

Monday, February 11, 2013

The 25 by ’25 Renewable Energy Initiative for New Hampshire – Can We Do It? - Part 1

With a new governor in place, I have been giving some thought to the initiative enacted by Governor Lynch in 2007 that New Hampshire should aim to get 25% of its energy from renewable resources by 2025 – the so-called 25 x '25 initiative. With my recent posts on renewable sources and their contribution to the NH energy supply, I was wondering how we are doing and if we are making progress towards the 25 x '25 goal. Until a few years ago, the New Hampshire Office of Energy and Planning, OEP, had been calculating and recording our progress, but they have not updated their information in a while. The last available numbers were for 2008 so in the next few posts I will be presenting updates of the OEP numbers and will be taking a closer look at the feasibility of the 25 x '25 goal and what it will take to achieve it.  

The goal is 25% renewable energy by 2025 but we need to start off by asking the question: "25% of what?" According to the OEP, the "what" is net energy usage. Net energy use refers to the energy we use in-state and excludes that associated with any energy exports. In our case, we export 51% of our produced electricity, so we need to subtract the energy used to produce this exported electricity from the gross, or overall, energy usage by NH to generate the net energy number.

All my blog posts and previous calculations, to this point, have referred to overall energy use by New Hampshire, so for net energy usage we need to reduce the 409 trillion BTU overall usage by the 113 trillion BTU used to produce exported electricity, leaving us with a new number: 296 trillion BTU. This is our net energy usage for New Hampshire for 2010 and will be the basis for the calculations and discussion for the next few blogs.

With the net in-state energy usage in hand and using the renewable energy numbers from previous blogs, we should be ready to calculate the percentage of renewable energy. Ah, if only it were so straightforward. Instead, we now face an intriguing dilemma: this revolves around how we look at that exported energy (electricity exports plus the energy waste associated with its production). The electricity produced in NH comes from renewable and non-renewable sources and even though the electrons involved in electricity flow from these sources are indistinguishable, we can view our produced electricity as a blend of green electrons (those from renewable energy) and brown electrons (those from fossil fuels and nuclear). So, when we export electricity are we exporting just brown electrons or a blend of green and brown electrons? As I have noted the electrons are indistinguishable, so we are, in essence, just playing an accounting game but this is an important game with important consequences. If we take the position that exported electricity is indeed a blend of green and brown electrons then we need a commensurate reduction in the amount of renewable energy we can claim for in-state use. Specifically: we export 51% of electricity production, so we need to reduce the renewable fraction that goes into electricity production by 51%. This significantly reduces the amount of renewable energy we can claim. On the other hand, if we take the position that we use all the green electrons in-state, then we can claim all that renewable energy that goes into electricity production.

Which is the correct answer? Well, the OEP sidesteps the issue of the correct answer by calculating the percent of renewable energy data for both scenarios. In my calculations, I adopted that same convention by performing calculations for both scenarios as well. The results of my calculations for 2010 are shown in the following table. I have used headings and formats similar to the OEP results to make for direct comparison. However, it should be noted that my methodology is a little different from that of the OEP as I have used the NH data and energy accounting approach from the Energy Information Agency, EIA, exclusively and I do not include imported electricity in accounting for renewables - even though it might be from hydroelectric operations in Canada.


At first glance, the results are not encouraging. Even if we lay claim to all the green electrons for in-state use, Option 1, we are at 14.7% renewable energy with 13 years to go. The situation is even worse if we calculate on the basis that we are exporting a blend of green and brown electrons, Option 2. In this case, we are only at 9.1% renewable energy. However, this still begs the question – which is the correct number? Well, it depends on who is playing the game and making the rules. Nevertheless, my vote is for the higher number, the one comes from grabbing all of the green electrons for ourselves. The basis of my choice that the calculation is simpler to perform, and this is an extraordinarily complex scientific reason - it is a larger number - which makes the 25% easier to achieve!

Feeling somewhat gloomy about where we presently stand, I wanted to see if we were, in fact, making progress since the 2007 start of the 25 x '25 initiative. If we were - and it was rapid progress – it would certainly be encouraging. I therefore went back a few years to calculate the percent renewable data for both options which I have presented in the chart below. I have included the earlier OEP numbers (shown as red X's) in the chart below and even though, as noted earlier, my methodology is somewhat different from that of the OEP, the agreement between the two data sets is good.




Since the start of the initiative in 2007, we have, using Option 1, gone from about 12% to almost 15% renewable energy which is commendable progress over the past 3 years. (With Option 2, we have only gone from 7.5 to 9.1% which is not as commendable and therefore, for the "complex" scientific reasons noted above, we will ignore it going forward.) At this rate – about a 1% increase per year – reaching 25% by 2025 looks achievable, which is rather encouraging. However, while we are basking in the warm glow of our collective achievement, let's take a closer look at the two sets of data that generated this chart. Specifically, let's examine net energy usage and renewable energy production in NH separately, which I have done in the bar chart below.


A closer review of this data reveals that most of the change in the renewable energy fraction has occurred as a result of the reduction in the in-state energy consumption over the past few years. We have gone from 325 trillion BTU in 2005 to 295  trillion BTU in 2010 – an impressive 9% decrease in 5 years (an annual compounded decrease of 1.9%) but, and this is rather crucial, an examination of the renewable data shows that there has been little change in the amount of renewable energy we produce in-state. As a result, we need to conclude that our progress toward the 25% renewable energy goal to date has been on the back of energy savings - and not from increased renewable energy.

Going forward, can we continue to rely on further energy savings to get us to 25% and how realistic is this? It also requires us to ask the question – where are these energy savings coming from – are they the result of a general economic slowdown in the state accelerated by the Great Recession, high energy prices, a shrinking population, the success of energy savings programs, or some other reason? This is certainly worth closer examination and I would be interested in your opinion. For the moment, and for an energy savings geek such as myself, regardless of the reason these energy reductions are positive and are certainly propelling us towards our goal. But we should stop here and ask ourselves - are they sustainable? In my next post, I will look at how net energy usage is allocated in the state and what we need to do in terms of more energy savings and/or renewable energy increases to achieve the 25 x '25 goal. It might be more difficult than we think.

 
Until next time, remember to turn off those lights when you leave the room.

Mike Mooiman
Franklin Pierce University
mooimanm@franklinpierce.edu
2/10/2013






 


Sunday, January 20, 2013

Another View of Statewide Energy Flows in New Hampshire

In this post I want to look at New Hampshire energy flows in a different way, without resorting, as I have in previous posts, to column charts and criss-crossing cobwebs of arrows. Instead, I would like to introduce the concept of Sankey, or flow, diagrams which are often used in the energy industry. In these diagrams the magnitude of the flow of energy is indicated by the width of the arrow. These diagrams were first used in the energy field by an Irish engineer and captain in the British army, Matthew Henry Phineas Riall Sankey in 1898 to illustrate energy flows in steam engines. A modern version of a Sankey diagram is shown in the next figure. This figure neatly shows how input energy into a steam engine is lost to smoke, friction and a large portion to the steam condensation step. The condensed water is then recirculated to be heated into steam again, hence the small recirculating flow. Useful energy as forward motion of the steam engine and a small amount going to the alternators is shown as the exiting blue flows.


The great thing about Sankey diagrams is that they are not restricted to only energy flows. They can be applied to quantities of many types. For example, material and cost flows are often depicted. One of the most famous of these flow diagrams is that prepared by the French engineer George Charles Minard in 1869, shown below. This figure illustrates the fate of Napoleon's army in 1812 -1813 as they progressed through their disastrous Russian invasion. The figure shows, by the width of the lines, the fate of the invading army. Napoleon crossed into Russian with 422,000 men and through attrition, minor skirmishes and some great battles he entered a largely abandoned Moscow with about 100,000 men under his command. He then turned back to return to France: on the way back, starvation, battles and incessant harassment by guerilla forces decimated his army to 10,000 survivors. The harsh winter also took its toll on his men - the line graph below the flow diagram shows the decreasing temperatures encountered on the army's return from Moscow. The diminishing width of the flow is a skillful, albeit rather harrowing, representation of what was happening in the army in the field, the prisoners that were taken and the lives that were lost.





But I digress. Let's return to energy flows. The folks at the Lawrence Livermore National Laboratory (LLNL) annually prepare flow diagrams for the
total flow of energy in the US. These diagrams are particularly useful and informative and they appear in energy-related presentations all over the place. In 2011 LLNL prepared individual diagrams for all 50 states based on 2008 data. To the best of my knowledge, they don't update these state diagrams every year like their total US flow diagram. Nevertheless I thought I would share their 2008 diagram for New Hampshire, shown below, with you.

 


Much of this figure shows the same information as my previous analysis, but it does so in a more elegant fashion. Off to the left, you can see the energy inputs to the state. These input energies then flow into transportation, homes, offices, stores and industry and a large part of the flow goes into electricity generation. The width of the lines clearly shows the magnitude of the flows. As with my analysis, it can be seen that electricity produces a lot of waste heat and a relatively small portion, 32% according to LLNL, ends up in electricity that is directed to homes, businesses, factories or exported out of state.


What this diagram includes, which my previous analysis did not, is the recognition that a large fraction of the energy that goes into transportation is lost as waste heat rather than motion. According to the LLNL estimates, only 25% goes into motion. They also recognized that a lot of the heat that goes into warming our homes, businesses and factories is lost due to poor insulation, waste and equipment inefficiencies. Their numbers suggest that 35% of the input energy into homes is lost. For commercial operations they estimate 30% of the energy is lost and losses of 20% are encountered in industrial applications. The diagram then neatly combines all the separate waste energy flows into a single value at the right of the diagram which illustrates the rather sobering fact - that, of the 418 trillion BTU energy supply to NH, 270 trillion BTU, or 65%, is lost as waste heat!

While not as dramatic as the fate of Napoleon's army, this single sobering fact that 65% of our energy input is lost provides the best opportunity for managing our energy needs going forward. Investments in higher efficiency equipment, higher mile-per-gallon vehicles and better insulation for our buildings will all serve to reduce the amount of energy wasted. This will reduce our input requirements. Energy supplies, especially those associated with fossil fuels, can be reduced and better managed. In the process we will reduce our carbon emissions as well.

In many respects, this is the most single beneficial thing that you and I can do at present – we can and we must reduce the amount of energy we waste. Yes, alternative energy sources are necessary but, while we are waiting for scientific breakthroughs and large-scale commercial development, we can be taking measures right now to reduce our energy consumption. We as individuals can take action and we can organize to get the organizations we work for to take action. There is lots of help out there. Many companies and non-profits are working in this field and they are making a difference. For example, here in New Hampshire the very focused mission of the Jordan Institute is to reduce energy losses from buildings in the State. They are doing some impressive things to reduce our dependence on fossil fuels. Take a look at their website if you get an opportunity.

We also need to be realistic about these losses. Yes, they are large, but we will never be able to totally eliminate them due to the nature of energy, materials, electricity and the laws of physics. Even so, we are so far away from these physical limits that there is a lot we can do to reduce energy waste.

So there you have it – another way to look at energy flows in the state. Bear in mind that this analysis uses 2008 figures from the Energy Information Administration and does not reflect the rapid switch away from coal that we are presently undergoing. I plan to present an update of the energy flow diagram for NH in a future post but, in the meantime, hopefully I have got you thinking about what you can do avoid energy losses in your home and the building you work in.


Until next time, remember to turn off those lights when you leave the room.


Mike Mooiman
Franklin Pierce University
mooimanm@franklinpierce.edu
1/20/2013