This is an updated post from my ongoing series on The Great Clean Tech Talent Gap, which I painfully experienced while trying to staff my growing renewable energy startup.
It has shocked me over the years how deep the shortage is of mechanical engineering skills in the renewable energy industry. When I say this, the first response is usually: “But renewable energy is related to power generation and electricity. Wouldn’t we need more electrical engineers?” NO! Wrong.
This widely-held belief — that energy-related topics fall mostly under Electrical Engineering (EE) — is harming the industry’s growth, hurting innovation, and are a lost opportunity for MechE professors to win research funding.
- GE 600kW solar inverter. Height: 7’8″, Weight: 7000 lbs.
Contents: 25% Electrical Engineering. 75% Mechanical Engineering.
This topic is important because we need more U.S. students to become engineers…and once they decide to become engineers, we need them to specialize in areas where they’re most needed. Many students enter the field that they think will provide the best job prospects. When my classmates and I were picking our majors in college during the heat of the dot-com boom, everybody was flocking to EE and Computer Science (CS) departments. English majors were entering the CS department and suffering through three years of courses they hated in order to improve their job prospects. No wonder half of my EE and CS classmates went to Wall Street or other non-tech jobs after the bubble burst during our senior year.
My college degree says I’m an electrical engineer with a focus on embedded controls, which is heavily software-based. Through experience, however, I’m a power electronics engineer, embedded controls engineer, engineering manager, technical sales moonlighter, and entrepreneur. I believe this mixture has given me a good perspective on what training I was lacking despite attending one of the best engineering schools in the world and therefore had to teach to myself or supplement through hiring.
In the past five years, new research centers have been sprouting up on college campuses around the country, including the following. Note that this is not an exhaustive list, so if I’m missing one please send me the link. For a list of schools that have strong energy and power programs, see the end of this post.
- Carnegie Mellon Smart Grid Research Center (2010)
- NC State FREEDM Systems Center (2008)
- Princeton Adlinger Center for Energy and the Environment (2008)
- MIT Energy Initiative (2006)
- Virginia Tech Center for Power and Energy (1985)
Princeton’s center is headed by a MechE professor and MIT’s is headed by a physics professor. All others are spearheaded by EE departments. While the centers usually try to be cross-disciplinary, it’s difficult…professors are busy focusing on their own, ongoing research. With renewable energy depending so heavily on mechanical engineering skills, I believe these centers represent lost opportunities for funding really interesting and impactful MechE research. Improving the integration of the necessary disciplines presents opportunities for boosting the effectiveness of the government’s research dollars.
Examples of Renewable Engineering
(If you’re willing to take my word for it and aren’t interested in the technical details, then just skip to the end of the list below.)
Other than the obvious — like designing wind turbine blades and towers – here are some examples of the work that goes into designing some critical components within any renewable energy system. You’ll notice that they’re all taught in mechanical engineering departments.
- Reliability under extreme conditions: One DOE manager told me that a major solar inverter manufacturer was providing sheepalong with their product. He was serious. The inverters were located in the middle of nowhere, so instead of mowing the lawn and having the grass clippings clog the ventilation intakes, the sheep took care of a major reliability and maintenance headache.Renewable energy systems not only need to survive but they also need to continue operating optimally and safely under extremely hostile environmental conditions: in the baking sun, under strong winds, exposed to salt water spray, in downpours where the rain comes in horizontally, under condensing humidity, subjected to lightning strikes, and in grimy industrial environments. They need to do this, ideally, for 20 years with only nominal maintenance and minimal degradation of performance. We need MechE’s!
- Control Theory and Modeling/Simulation: I haven’t seen a single renewable energy system that isn’t saddled with control problems. Power converters require control of their switch trigger timings. Motors and generators require specialized controls, which vary widely based on how they’re constructed. The grid as a whole requires complex distributed controls to remain stable. Wind turbines require controls for the pitch of their blades to maximize energy capture and other critical controls to make sure they don’t fly apart during a grid outage. Even stationary hardware like PV panels and batteries require max power tracking and charging/discharging controls, respectively. Smart grid components such as thermostats require controls. The list is endless. Control theory courses are usually taught in the MechE department.In dot-com product development, if your code fails then just reboot your crashed computer. In renewable energy development, if your code fails then your hardware blows up, you lose thousands of dollars, and someone could get injured. Renewable energy equipment is so large, expensive, and energetic that systems must be modeled and simulated long before anything is built. We need people who can perform these simulations in a realistically yet efficiently.
- Mechanics (mounting heavy components, designing for shock & vibration): Power equipment is heavy (minimum of 20-100 lbs for residential, 500-2000 lbs for commercial installations, and much higher for industrial utility-scale systems). For these heavy components, mounting considerations and shock and vibration stresses during transport are incredibly important. I’ve seen several pieces of hardware (typically $5,000 to $20,000 apiece) get destroyed in transit due to overlooked mechanical design considerations.
- Enclosure / packaging design: Between 25-44% of a solar installation is the “balance of system” cost (mostly mounting hardware) and installation labor. The high-tech solar panels are only 50% of the cost. MechE’s have the same potential to reduce the cost of solar installations as the well-funded photovoltaic cell researchers receiving billions of dollars in government and VC funding. The large size of renewable energy systems drives materials cost, manufacturing labor, inventory overhead, shipping costs, and installation costs. In most cases, a MechE needs to figure out how to pack 2 pounds of stuff in a 1 pound bag or how to assemble things faster.
- Magnetics: Motors, generators, inductors, and transformers are all examples of magnetics. Several magnetic components are found in every single solar, wind, electric vehicle, and power distribution box. I’ve seen that MechE’s are the best at the 3-dimensional visualization of the cores, windings, and magnetic flux lines, which is necessary in doing the magnetics design. This is a lost art and I can count on two hands the number of engineers I’ve encountered who are good magnetics designers. If you want job security, teach yourself magnetics design.
- Thermodynamics (thermal and airflow design): This is a huge topic and a huge challenge. To put it in perspective with one example: an industrial-scale solar inverter dissipates in losses the same amount that 2 to 4 homes consume. All that power needs to be dissipated out of just six brick-sized components. Doing that without overheating anything…over a period of 10-20 years…is a huge mechanical engineering challenge.
- Rotating machinery: Many renewable energy systems, most energy efficiency improvements, and all electric vehicle systems include a rotating machine like a motor or generator. I’ve run into the problem way too many times of having an EE who doesn’t understand how the machine works and a MechE who doesn’t know how the power system works…and the two don’t speak the same engineering “language.”
- Materials: Capacitors are designed by chemists and physicists, but their reliability and cost are determined by the MechE who packages them. Batteries are designed by chemists, but MechE’s make the packaging safe. They also make sure the materials inside every type of renewable energy system don’t corrode under salty, humid, or high-voltage conditions.
We need more renewable engineers with mechanical engineering skills!
Tear Down the Silos
It’s risky for me to make such broad generalizations. Someone can easily say “XYZ skill is purely EE or chemistry” or “the best engineers are cross-disciplinary.” I recently visited MIT and spoke with a computer science professor. He knew virtually no EE professors and referred to the various departments as “silos,” with little interaction between them. From my own experience, I know that undergrad education doesn’t cross disciplines very frequently…after taking their electives, students typically need to focus the majority of their course load on their specific major. Freshman be forewarned: if you know which industry you want to enter, you need to make sure you get the appropriate mix of classes, regardless of how the departments and curriculum are structured.
As for the research centers…from the outside it seems that MechE professors are not seizing on the opportunity to become the leaders in renewable energy research and education. Maybe the issue is that MechE departments have focused on airfoils and engines for so long that it’s difficult to jump into this 21st-century industry which also requires EE skills as well. Maybe this is a sign that the traditional divisions between MechE and EE are outdated.
Regardless of the reason, if universities want to become leaders in renewable energy research and want to create the highest-performing engineers in this hot field, then topics that have traditionally been taught in the mechanical engineering department need to become requirements for anyone interested in renewable energy.
I’ve received some interesting responses to this post, especially the following from Yogesh Nama:
Erik, There is no shortage of mechanical engineer. How many do you want?? Most of recruiters in the US and UK simply do not bother to look at the CV properly. They simply run a search for a keyword. If it’s not in the resume then the candidate isn’t considered for the job.
In this post I tried to make the argument that either (a) we need more mechanical engineers with an inclination towards working in renewable energy and the necessary additional skills to work on renewable engineering technologies or (b) we need to cross-train EEs in traditional mechanical engineering skills. I’m sure there are plenty of MechE’s being trained with the skills necessary to work at Ford or Boeing…and enough EE’s with the skills to work at Intel…but very few with the necessary mixture of skills to excel in renewable energy work.
Renewable energy engineers don’t just need the standard materials, mechanics, and thermodynamics training necessary to build airplanes and cars…they need slightly broader training. If they did have that training, I believe they would be the best for most clean tech engineering jobs.
As for the comment about keywords on resumes…I completely agree. Reviewing resumes that are receive “over the transom” for keywords and just spending one hour interviewing someone results in poor hiring results. References and working with someone on a trial basis are the only way to know for sure whether a person is a good fit for the position and the company’s culture.