Home fuel cell

Key takeaways

Home fuel cell belongs to biology; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Home fuel cell to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Home fuel cell from memory before moving on to harder problems.

Reference excerpt

A home fuel cell or a residential fuel cell is an electrochemical cell used for primary or backup power generation. They are similar to the larger industrial stationary fuel cells, but built on a smaller scale for residential use. These fuel cells are usually based on combined heat and power (CHP) or micro combined heat and power (m-CHP) technology, generating both power and heated water or air.

Uses Home fuel cells are installed alongside grid-provided mains power to consistently produce the exact amount of electricity and heat needed. Additionally, a home fuel cell may be combined with a traditional furnace that produces only heat. For example, the German company Viessmann produces a home fuel cell with an electric power of 0 kW and a thermal power of 1 kW, integrated with a traditional 19 kW heat-producing furnace, using the grid for electricity needs below and above the fuel cell production. PEMFC fuel cell m-CHP operates at low temperature (50 to 100 °C) and requires high-purity hydrogen. It is prone to contamination, and changes can be made to operate at higher temperatures and improve the fuel reformer. The SOFC fuel cell m-CHP operates at a high temperature (500 to 1,000 °CP) and can handle different energy sources, but the high temperature requires expensive materials to handle the temperature. Changes can be made to operate at a lower temperature. Because of the higher temperature, SOFCs in general have a longer start-up time.

Environmental impact Because the home fuel cell generates electricity and heat that are both used on site, theoretical efficiency approaches 100%. This is in contrast to traditional or fuel cell non-domestic electricity production, which has both a transmission loss and useless heat, requiring extra energy consumption for domestic heating. The home fuel cell cannot generate exactly the needed amount of both heat and electricity at all times. Therefore, they are typically not a standalone installation, but are rather combined with a traditional furnace and connected to the grid for electricity needs above or below that produced by the fuel cell. As such, the overall efficiency is below 100%. The high efficiency of home fuel cells has caused some countries, such as Germany, to economically support their installation as part of a policy reacting to climate change.

Installation Home fuel cells are designed and built to fit in either an interior mechanical room or outside, running quietly in the background 24/7. Connected to the utility grid through the home's main service panel and using net metering, the home's fuel cells can easily integrate with existing electrical and hydronic systems, and are compliant with utility interconnection requirements. In the event of a grid interruption, the system automatically switches to operate in a grid-independent mode to provide continuous backup power for dedicated circuits in the home while the grid is down. It can also be modified to run off the grid.

Current installations Twenty companies have installed Bloom Energy fuel cells in their buildings, including Google, eBay, and FedEx. The CEO of eBay told 60 Minutes in 2010 that they had saved $100,000 in electricity bills in the 9 months since they were installed. Oregon-based ClearEdge Power had until 2014 installed 5 kW systems at the homes of Jackie Autry, Bay Area Wealth Manager Bruce Raabe and VC investor Gary Dillabough. A commercially working cell in Japan called Eni-Farm is supported by the regional government, using natural gas to power the fuel cell that then produces electricity and heated water. In 2013, 64% of global sales of the micro-combined heat and power fuel cell surpassed the conventional mechanical rotary systems in sales in 2012.

Life cycle Fuel cells have an average lifetime of around 60,000 hours. For PEM fuel cell units, which shut down at night, this equates to an estimated lifetime of between ten and fifteen years.

Cost Most home fuel cells are comparable to residential solar energy photovoltaic systems on a dollar-per-watt-installed basis. Some natural gas-driven home fuel cells can generate eight times more energy per year than the same-sized solar installation, even in the best solar locations. For example, a 5 kW home fuel cell produces about 80 MWh of annual combined electricity and heat, compared to approximately 10 MWh generated by a 5 kW solar system. However, these systems are not directly comparable because solar power is a renewable resource with basically no operating cost, while natural gas is neither. Operating costs for home fuel cells can be as low as 6.0¢ per kWh based on $1.20 per therm for natural gas, assuming full electrical and heat load utilization. Residential fuel cells can have high initial capital costs . As of December 2012, Panasonic and Tokyo Gas Co., Ltd. sold about 21,000 PEM Eni-Farm units in Japan for a price of $22,600 before installation.

Incentives In the US, home fuel cells are eligible for substantial incentives and rebates at both the state and federal levels as part of renewable energy policy. For example, the California Self Generation Incentive Program (SGIP) rebate ($2,500 per kW) and Federal Tax Credits ($1,000 per kW residential and $3,000 per kW commercial) significantly reduce the net capital cost to the customer. For businesses, additional cash advantages can be realized from bonuses and accelerated depreciation of fuel cells. In addition, home fuel cells receive net metering credit in many service areas for any excess electricity generated but not used by putting it back on the utility grid. The Database of State Incentives for Renewables & Efficiency (DSIRE) provides comprehensive information on state, local, utility, and federal incentives that promote renewable energy and energy efficiency.

California In California, in particular, utilities charge higher per kWh rates as energy consumption rises above established baselines, with the top tier set at the highest rates to discourage consumption at those levels. Home fuel cells reduce customer exposure to the top-tier rates, saving homeowners as much as 45% in reduced annual energy costs.

Market status

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Worked examples

Example 1 — a first encounter with Home fuel cell

Start with the simplest possible case. Write down what Home fuel cell claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In biology, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Home fuel cell before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Home fuel cell ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Home fuel cell

In research: Home fuel cell appears in biology research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Home fuel cell in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Home fuel cell is common in secondary-school and first-year university syllabi. It links to neighbouring topics Fuel cells, Residential heating, so understanding it makes those chapters shorter.
In everyday life: Look for Home fuel cell outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

How to study Home fuel cell in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Home fuel cell means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Home fuel cell out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Home fuel cell in simple terms?

A home fuel cell or a residential fuel cell is an electrochemical cell used for primary or backup power generation. They are similar to the larger industrial stationary fuel cells, but built on a smaller scale for residential use.

Why does Home fuel cell matter?

Because it connects several biology ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Home fuel cell?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Home fuel cell.