Updated on January 18, 2024


Created on August 27, 2015

Sun King Eco

Upcoming Update

A solar-powered study lamp with pay-as-you-go functionality.

Developed By
  1. Sun King
Tested By
  • Lighting Global
  • MIT D-Lab
Content Partners


Product Description

Greenlight Planet SunKing Eco Pay As You Go (PAYG) Angaza Eco: Solar study light with pay-as-you-go financing option.

Note that as of July 2016, this product is no longer in production.

Target SDGs

SDG 7: Affordable and Clean Energy

SDG 8: Decent Work and Economic Growth

Market Suggested Retail Price


Target Users (Target Impact Group)


Distributors / Implementing Organizations

Greenlight Planet's distribution network. Distributed in India by EssMart. Online distribution via Amazon

Competitive Landscape

Manufacturing/Building Method

Mass Produced.

Intellectural Property Type

Select Type

User Provision Model

Initially through Greenlight Planet's distribution network and eventually through their partners.

Distributions to Date Status

Unknown. (product launched in January 2015)

Lamp type


Number of light points


Total light output (lumens)

Low: 4 lumens, normal: 10 lumens, high: 25 lumens

Multiple brightness settings (yes/no)


Light duration on single charge (hr)


Mobile charging (yes/no)


Power source

Solar Panel

Battery type

Lithium Iron Phosphate

Peak power rating (Wp)


Battery capacity (kWh; mAh)


Battery nominal voltage (V)


User replaceable battery (yes/no)


User replaceable light (yes/no)


Design Specifications

The SunKing Eco is designed to be paid off over the course of 10 weeks using an imbedded chip in the solar lantern and mobile payments. The solar lantern has three brightness settings and can run continuously on its normal setting for 8 hours on a full charge. Dimensions: 26.16x17.78x15.24cm, 0.5443kg

Product Schematics

Technical Support

Greenlight Planet (now Sun King)

Replacement Components

Replacement batteries, as well as replacement battery specifications, are available from the product manufacturer.


Warranty: 2 Years

Manufacturer Specified Performance Parameters

Targets: 25 Lumen output, 30 hours of light on one day's charge, 5 years of battery life, lightweight, high durability,

Vetted Performance Status

Results from Lighting Global Turbo (not tested on Medium or Low settings): Battery run time (8.1 hours); Run time per day of solar charging (8.1 hours); Total light output (27 lumens); Total area with illumination > 25 lux (220 m2) The Comprehensive Initiative on Technology Evaluation (CITE) at MIT evaluated personal-use solar lanterns available on the market in Uganda and published the results in January 2015. The SunKing Eco received a score of 50/100. Full findings are available in their report and as a snapshot synopsis is available in the image included here.



Complementary Technical Systems

Payment: Mobile phone access facilitates easier payments for product.

Academic Research and References

Chen, W., Lemes, A., Moorthy, A., Strickland, L., Zhu, Y., Renewable energy at the base of the pyramid in haiti [Internet]. Ann Arbor (MI): University of Michigan; 2014 Apr 22 [cited 2015 Jun 10].

Austin-Breneman, J., Yang, M., Design for micro-enterprise: an approach to product design for emerging markets. ASME IDETCCIEC. 2013 Aug 4-7;5:11 p.

Kher, R., Streeter, D., Greenlight Planet: made in China or made in India? Journal of the International Academy for Case Studies. 2013 Oct;19(7):31 p.

Pailman, W.L., Kruger, W., Prasad, G., Mobile payment innovation for sustainable energy access. DUE. 2015 Mar 31-Apr 1;2015 International Conference:39-44.

Solanki, C.S., Mudaliar, S., Strategies to target rural PV market in developing countries – a perspective. PVSC. 2010 Jun 20-25;35:2392-2396.

Dzombak, R., Mehta, C., Mehta, K., Bilen, S.G., The relevance of systems thinking in the quest for multifinal social enterprises. Systemic Practice and Action Research. 2013 Dec 14;27(6):593-606.

Planet, Greenlight. n.d. Greenlight Planet Launches Sun KingTM Eco Easy Buy in Kenya Powered by Angaza Design. www.prnewswire.com.

IEC TS 62257-9-5:2018 | IEC Webstore. n.d. webstore.iec.ch.

Amazon.com: Greenlight Planet Sun King Eco Portable Solar Lantern – Discontinued : Sports & Outdoors. n.d. www.amazon.com.

Lighting Global. 2013. Specifications Sheet: Sun King Eco. Lighting Global.

MIT D-Lab | CITE. n.d. D-Lab.mit.edu.

Asher J. et al. 2015. Experimentation in Product Evaluation: The Case Study of Solar Lanterns in Uganda, Africa. dspace.mit.edu. Cambridge, MA, USA: Massachusetts Institute of Technology (MIT).

Quality Standards. n.d. Verasol.

Previously Certified Products. n.d. Verasol.


Compliance with regulations

In compliance with Lighting Global, Global Quality Standards: Truth in Advertising Lumen Maintenance Quality Warranty IEC 62257-9-5 ed 2.0 Polycarbonate & ABS IP64 rated

Evaluation methods

Greenlight Planet Sun King Eco was tested according to the Quality Test Method in the latest edition of IEC 62257-9-52 and met the Lighting Global Quality Standards. The Comprehensive Initiative on Technology Evaluation (CITE) at MIT evaluated personal-use solar lanterns according to comparative framework for evaluation of products, similar to the model used by the U.S. nonprofit organization Consumer Reports along the dimensions of Suitability, Scalability, and Sustainability. Students and faculty collected data on 11 solar lantern models from both field and laboratory tests, as well as through interviews, surveys, and participant observation of product users and Solar Sister distribution agents.

Other Information


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