physics

L Prize

L Prize is a physics topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand L Prize rather than just read about it. In short: The L-Prize competition was designed to spur development of LED light replacements for 60W incandescent lamps and PAR38 halogen lamps as well as an ultra-efficient "21st Century Lamp". It was established by the United States Department of Energy (DOE) as directed by the Energy Independence and Security Act of 2007.

Key takeaways

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

Reference excerpt

The L-Prize competition was designed to spur development of LED light replacements for 60W incandescent lamps and PAR38 halogen lamps as well as an ultra-efficient "21st Century Lamp". It was established by the United States Department of Energy (DOE) as directed by the Energy Independence and Security Act of 2007. The original competition, launched in 2008, focused on an LED replacement for the common 60-watt light bulb and this L-Prize was awarded in 2011. The PAR38 competition was launched but received no entries and was suspended in 2014. The 21st Century Lamp competition was never opened. The current L-Prize Competition launched in 2021 and targets commercial-sector lighting, which accounts for about 36% of lighting energy use in the United States.

2007 L-Prize Competition

60W Competition

The original L-Prize Competition, launched in 2008, sought LED replacements for the common 60-watt light bulb. In late 2009, the L-Prize competition received its first entry, from Philips Lighting North America. The 2,000 samples submitted by Philips went through a rigorous 18-month evaluation that included industry-standard photometric testing, stress testing under extreme conditions, and long-term lumen maintenance testing at elevated temperatures. In addition, field assessments were conducted by L-Prize partners to see how the product performed in real-world settings. The Philips entry met all requirements and, in August 2011, was declared the L-Prize winner in the 60W replacement category. The product became available in the retail market on April 22, 2012 (Earth Day). The lamp was comparable to a 60W incandescent in color quality (CRI = 93, CCT = 2727 K), light distribution, and light output (940 lumens) but consumed less than 10W (a savings of 83%), and at 25,000 hours of testing, the actual lumen maintenance was 100%, with chromaticity change at less than .002.

PAR38 and 21st Century Lamp Competitions The L-Prize competition to develop LED replacements for PAR38 halogen lamps was launched but received no entries and was suspended in 2014. The 21st Century Lamp competition was never opened.

2021 L-Prize Competition

The goal of the new L-Prize is to spur development of next-generation LED lighting systems for commercial buildings. Challenging technical requirements put in place by DOE are intended to stimulate creative approaches that would raise the bar for efficacy, quality of light, connectivity, and life cycle environmental impact. In addition to technical innovation, the L-Prize encourages entrants to address diversity, equity, and inclusion (DEI) in the business practice, the supply chain, or other areas where they can effect change through the core business model and operations. The current L-Prize seeks interoperable lighting systems that demonstrate exceptional achievement in all areas. The current L-Prize has three distinct phases, and competitors can enter any or all phases.

Concept Phase The L-Prize Concept Phase invited innovative concept proposals documenting a luminaire and lighting system of the future. The Concept Phase completed in February 2022, with four winners announced by Energy Secretary Jennifer Granholm:

Project Tango, submitted by QuarkStar of Las Vegas, Nevada. The networked, white-tunable luminaire concept leverages innovations in optics, LED, and power conversion technology to deliver high efficacy, exceptional quality of light, and precise control of light distribution. Sustainable and Connected Troffer Retrofit, submitted by Orion Energy Systems of Jacksonville, Florida. The concept offers a high-efficacy, networked LED luminaire with advanced controls that can be retrofitted in less than two minutes to an existing fluorescent luminaire. Laterally Symmetrical Level 3 Engine for 3D Printing, submitted by Smash the Bulb/Bridgelux of Mountain View, California. This 3D-printed semi-indirect luminaire concept uses a high-performance light engine that requires no secondary optics and delivers high efficacy and excellent quality of light; an innovative optical design that reduces losses and addresses glare; and a luminaire housing that can be 3D printed on the job site. Papaya Modular Lighting Ecosystem, submitted by Papaya of Evanston, Illinois. This highly modular luminaire platform designed by a team from outside the lighting industry uses a unique community-based approach; an all open-source aspect offers opportunities for innovators of all types to participate in evolving and innovating this lighting solution over time.

Prototype Phase The L-Prize Prototype Phase invited physical, working prototype systems that emphasized technological innovation and challenged competitors to think outside the standard forms, materials, and price points of commercially available products. Competitors could submit products in the Luminaire Track, the Connected Systems Track, or both. Entries were scored across multiple criteria.

Luminaire Track Winners Generation Flex: Light Without Compromise, submitted by Signify Innovation of Bridgewater, New Jersey Low-Carbon Biodegradable Luminaire, submitted by Lightly of Boothwyn, Pennsylvania Helios HPR-LP160, submitted by Grid interactive Efficient Building Alliance (GiEBA) of San Diego, California

Connected Systems Track Winners Interact Next-Gen: Light the Way to Building Goals, submitted by Signify Innovation of Bridgewater, New Jersey Autani: Insights 4REAL, with Sensing by Leviton, submitted by Autani and Leviton of Columbia, Maryland Bluetooth Mesh Wireless Lighting Control System, submitted by McWong International of Sacramento, California

Manufacturing and Installation Phase The Manufacturing and Installation Phase is designed to reward production and installation of products meeting the L-Prize technical requirements. Up to four competitors earning the most points based on innovation, U.S. content, production, and installation will share an award of $10 million. Like the Prototype Phase, the Manufacturing and Installation Phase will feature two separate tracks: a luminaire track and a connected systems track. Under the rules, competitors could submit an entry for one track or separate entries for both tracks, and DOE will evaluate each track’s submissions independently.

References

… excerpt ends here. Continue reading the full article.

Illustrations

Worked examples

Example 1 — a first encounter with L Prize

Start with the simplest possible case. Write down what L Prize claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In physics, 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 L Prize 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 L Prize 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 L Prize

In research: L Prize appears in physics 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 L Prize 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: L Prize is common in secondary-school and first-year university syllabi. It links to neighbouring topics American science and technology awards, Challenge awards, Design awards, so understanding it makes those chapters shorter.
In everyday life: Look for L Prize 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.

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How to study L Prize in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what L Prize 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 L Prize out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is L Prize in simple terms?

Why does L Prize matter?

Because it connects several physics 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 L Prize?

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 L Prize.