Dec 19, 2018

SOx and NOx emissions reductions from coal fired electric power generation

SOx and NOx emissions

Coal accounted for more than 50% of U.S. electricity generation in 1997, and natural gas and renewables together accounted for 26% of generation. By 2017, coal-fired generation had declined to 30% of electricity generation while generation from natural gas and renewables grew to nearly 50% of electric power industry generation.
SOx and NOx emissions reduction from 1997 to 2017
Source and complete discussion at :


Apr 5, 2017

Human Robot Interaction (Cute)

Well, this assumes that the human thinks that interaction is with a robot.

Not sure what the robot thought, it remained silent this time around.  JK.

Saw this on twitter originally!


Dec 25, 2015

Local offgrid enthusiasts

I got a chance to visit a friend here in central PA who is setting up his property to be self sufficient on both energy and water needs.

 A quick photo log follows of some of the efforts at two locations.

Caption is above image.
Solar photovoltaic system (rooftop) and a solar thermal water heating system on the side of the barn wall.

PV system is 7kW and about 6-8 hours average sunlight in a day with peak between 11-3pm

Direct solar thermal water heater (in detail)
Water flows through a loop changing direction at the ends, this keeps it long in sunlight to heat up sufficiently. Higher absorbent coatings or color on the pipes help further.

Micro hydro potential.
While the drop is relatively small, it is possible to build a penstock system that takes water through a steeper drop to the side and after the turbine can be released back into the stream.

He also has electric cars and batteries hooked up to the PV system. Further, he has a van with solar panels installed in top for road auxiliary power as well as power for lights, electric stove etc when they park/camp.

He also has 2 diesel cars that run on used vegetable oil! That's waste oil being used as a fuel! The house heating is supplemented by local wood furnaces. A lot of dead trees can be used as firewood (at least in PA), he also used wood pellets, that burn cleaner and completely.

All in all it was a great visit!


Dec 21, 2015

Workshop on Power Systems and Markets - Penn State Nov 2015

Workshop on Power Systems and Markets 2015

Penn State [1], a leading research university recently launched the Center for Sustainable Electric Power Systems (CSEPS). This is "an interdisciplinary research initiative with focus on renewable power systems and markets."

CSEPS, led by Profs Mort Webster and Uday Shanbagh recently conducted a two day workshop on Power systems and markets (Nov 19,20 - 2015). I signed up for the workshop and attended several sessions on both days and learnt a lot of new things about power markets and also connected several dots inside my head between economic development, pricing power, strategy and island/remote area electricity supply.

Key Takeaways from CSEP workshop at Penn State:
1) Illinois Institute of Technology has built a full scale technology demonstration microgrid that powers their campus, saves peak power and has a simple payback period of about ~5 years. The project cost was $12 M but the DOE grant reduced the direct costs for IIT. 

Also, at UCSD, a 42 MW microgrid is operational and paving the way for the future.
At UCSD, the microgrid provides the ability to manage 42 megawatts of generating capacity, including a central cogeneration plant, an array of solar photovoltaic installations and a fuel cell that operates on natural gas reclaimed from a landfill site.  (link)

2. Dr. Paul Sotkiewicz (PJM) argued that heat rate improvements have caused lower CO2/MMWh. If my notes are correct, the numbers quoted were a total CO2 emission reduction of 115 million tonnes.

Some other interesting info bytes:
In this post, I will review some of the notes I gathered from two of the plenary sessions and some thoughts regarding applications into specific markets. The format will be introduction to speaker and topic, specific points from lecture, Q&A and Summary thoughts.

Technology and Policy Impacts on Electricity Markets

The opening plenary speaker was Dr. Paul Sotkiewicz, Senior Economic Policy Advisor at PJM Interconnection. He immediately won the attention of the audience (at least mine, for sure) with his dry wit and knowledge.  He has worked at the Federal Energy Regulatory Commissions and the University of Minnesota, and University of Florida, prior to PJM, so we got a treat listening to a very experienced professional with insights from academic, public and private perspectives. Before I say more about his lecture, it is important to stress on the scale of operations at PJM (an entity that covers 13 states now, although PJM originally used to be Pennsylvania Jersey Maryland).

Peak   - 165, 492 MW
Capacity - 183, 604 MW
2014 GWh - 837, 796
Population - 61 million

For comparison US total generation is nearly 4 million GWh:

Q & A:

One of the questions raised was if the electricity data includes any of the distributed generation from small scale solar and other renewable electric. The speaker mentioned that this is some data that they do not always have access. Update: A recent EIA news report seems to indicate that this data may be available soon.

Small-scale distributed solar photovoltaic (PV) systems, such as those found on residential and commercial rooftops, have grown significantly in the United States over the past several years. Starting this month, the U.S. Energy Information Administration (EIA) is including monthly estimates of small-scale distributed solar PV capacity and generation by state and sector in EIA's Electric Power Monthly.”

EIA estimates that total U.S. solar generation (PV and thermal) was 3.6 million megawatthours in September 2015, with 33% of that total coming from small-scale solar PV. Overall, U.S. solar generation, including both small-scale distributed PV and utility-scale PV and thermal solar generation, was equivalent to about 1.0% of total reported electricity generation from all utility-scale sources in September 2015.  

tags: natural gas, constrained, variable energy scheduling

Prof. Mohammed Shahidehpour

DC nanogrid running direct loads (computers and modified LEDs in gyms) help in cutting down costs of inverters/hardware. In effect they can reduce total loads by up to 56% and the test case showed that gymnasiums were able to reduce costs by about 50% (Presentation).

Cost of power on islands is typically about 50-55 cents/kWh. These costs can be brought down to about 30 cents/kWh by the use of microgrids.

[1]: The Pennsylvania State University, a large land-grant reseach institution in the Commonwealth of Pennsylvania, is located at State College PA and several other branch campuses through Pennsylvania and also has satellite locations in San Diego and collaborations with several institutions around the world. Note: I hold a Masters degree from Penn State Mechanical Engineering and am (/was) a PhD candidate in Energy and Mineral Engineering.

[2]:  Funded by the Earth and Mineral Sciences Energy Institute, the Center for Sustainable Electric Power Systems (CSEPS) brings together university faculty from a variety of disciplines—including engineering, economics, earth sciences and agricultural sciences—to develop innovative research projects that are centered on sustainable electric power.

Other Relevant Data:



Dec 17, 2015

The Economics of Battery Energy Storage -via RMI

Sharing The Economics of Battery Storage via Rocky Mountain Institute (External Link)

The Economics of Battery Energy Storage


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