• What is SolarCoin?
    SolarCoin is an alternative digital currency. SolarCoin is backed by two forms of proof of work. One is the traditional cryptographic proof of work associated with digital currency.  Another proof of work is a 3rd party verified meter reading. SolarCoin is equitably distributed using both of these proofs of work as a means to reward solar energy generation.


    Solar energy, unlike fossil fuels, does not place excess heat or carbon into the atmosphere. The long term intent is to provide an incentive to produce more solar electricity globally over the next 40 years by rewarding the generators of solar electricity.  SolarCoin is intended to shift the levelized cost of energy (LOCE). Source:solarcoin wiki

    Technical details relating to SolarCoin are on Github.com/solarcoin

    See what the World’s media is saying about SolarCoin.

  • How do I get SolarCoins?

    1. Download and install a wallet.

    2. Visit an online Charitable faucet run by 3rd party digital currency, Solar energy and environmental groups. A list of 3rd party faucets is maintained on the SolarCoin wiki page. Solar energy related charities may reach out to the SolarCoin Foundation for a SolarCoin grant for the charity and its members.

    3. Submit a proof of Solar electricity generation in the form of a 3rd party verified meter reading format based on your countries geography and or regulatory regime. 1MWh entitles you to §1 SLR coin.  On the Claim SolarCoins section of the SolarCoin.org site.

    4. Buy SolarCoin online on an exchange .

    SLR Grant

    4. Mine them like other alternative currencies: To mine them you need to download a SolarCoin wallet or join a mining pool.

  • How can I start accepting SolarCoins for my business or charity?

    1. Download a SolarCoin wallet from below.
    2. Find your SolarCoin address in the wallet application.
    3. Display your SolarCoin address or QR code on your website or on a physical sign.

    SolarCoin accepted here3
    That’s it! You can now receive SolarCoin as donations or payment for goods and services.

  • What is one MWh's worth of electricity?

    Each circulating SolarCoin represents 1MWh (megawatt hour) of solar electricity generated. Each MWh of renewable electricity displaces more than 1,500 lbs of carbon dioxide that would have been released by burning fossil fuels like natural gas and coal.

  • Who created SolarCoin and who is managing it?

    SolarCoin was created by a group of volunteers interested in creating a currency experiment to benefit the environment. SolarCoin is an open community project run by Volunteers working together as the SolarCoin Foundation.  Anyone can join and participate. See the volunteer page.  The SolarCoin Foundation is getting its charter together.  More early information is on the SolarCoin Wiki and SolarCoin SolarCoin forum

  • What is the SolarCoin Foundation?
    The SolarCoin Foundation is an international network of volunteers managing the distribution of SolarCoins to Solar Electricity Generators using 3rd party verified meter readings as the “proof of work”.

    The SolarCoin Foundation maintains a public ledger detailing each SolarCoin allocated to solar electricity generators. The transactions are also kept in the SolarCoin Blockchain.

  • When did SolarCoin start? How long is it going to last?

    SolarCoin was launched in January 2014.  The SolarCoin Foundation designed the supply of SolarCoin to last 40 years delivering incentives for generating 97,500 TWh of solar electricity. The SolarCoin network evolves as the adoption of the currency grows.

  • How are SolarCoins allocated?

    SolarCoins representing 97,500 TeraWatt hours of solar energy generation are held in reserve:

    • §105 Million SolarCoins (0.1%) will be mined. >98% of the §105 million minable SolarCoins will circulate in the next 6 years.  Mining generates 52.6 million SolarCoins in the first year halving each year after that. All publicly mined SolarCoins represent historically generated and unclaimed solar electricity. Technical specs are on github/solarcoin.  The Blockchain explorer is here.
    • §97.5 Billion SolarCoins (99.4%) are stored in the SolarCoin Foundation non-circulating generator pool account. These are to be exchanged for “proof of work” claims of solar electricity generation submitted over the next 40 years. Each 1MWh of solar energy is entitled to 1 SLR. According to the IEA were an estimated 147 Million MWh of Solar electricity produced by PV & CSP in 2013. This would equal 147 million potential SolarCoins claims.

    SolarCoin Issuance Process:

    -         Solar energy generated from a 3rd party verified meter reading

    -         SolarCoin Foundation & community verifies claim and records issuance in public ledger

    -         SolarCoin Foundation transfers coins from reserve account to claimant (visible in the blockchain)

    -         SLR claimant spends / circulates coins using wallets etc.

    • §500 Million SolarCoins (0.509%) in the genesis pool account representing environmental charities, early volunteers, advisers, builders and maintainers of SolarCoin infrastructure will circulate.  Genesis pool circulation is restricted to never being more than 5% of total SolarCoin in circulation.
    SolarCoins have been granted to 14 out of 215 countries so far. Claim SolarCoins here.
  • How can SolarCoin currency be environmentally friendly?
    SolarCoin is intended as a mechanism to incentivize generation of global solar electricity. Solar power is an abundant, renewable energy source that avoids pollution from conventional coal and nuclear plants. Every megawatt-hour of electricity generated through a solar PV panel avoids more than 1,500 lbs of carbon dioxide (CO2), more than 5 lbs of sulfur dioxide (SO2), and almost 2 lbs of nitrogen oxide (NOx), and it also avoids producing radioactive nuclear wastes.  Solar energy production is highest on hot, sunny days when air conditioners are running and electricity demand peaks.  By providing energy during peak demand times, that same solar energy that warms an area can be captured and used to power those devices.

    bitcoin solarcoin carbon footprint

    Using a marginal utility model based on Blockchain rewards, SolarCoin is estimated to be >50 times more energy and Carbon efficient than Bitcoin. Lower Carbon Currency Model explanation in wiki. Feel free to critique, enhance and propose a better carbon model Google Doc spreadsheet is here. Excel Spreadsheet model download.

    This estimate doesn’t include the effects SolarCoin may have on Solar energy generation. When the incentive for solar electricity generation is figured in, SolarCoin is likely to be extremely good for Carbon Reduction.  The SolarCoin Foundation welcomes those wishing to present models or papers supporting or refuting this early thesis.

  • How is SolarCoin different from Bitcoin?

    SolarCoin is not a replacement for Bitcoin. It is a complementary currency using Bitcoin technology implemented to incentivize global Solar electricity generation over the next 40 years.



    Incentivize global solar electricity for the next 40 years.


    Create a decentralized currency

    SolarCoin Foundation


    Satoshi Nakamoto


    Launch date


    Open source community

    Project support

    Open source community

    §98.10 billion

    Maximum issuance

    21 million

    <§16 million

    Current circulation

    >11 million

    Est. §60 million (§50 million mining §10 million charitable grants)

    Next years circulation increase

    Est. 1 million

    Free market supply & demand

    Currency target value

    Free market supply & demand

    Coins & paper wallets (bills) coming soon.

    Physical format

    Coins & paper wallets (bills)

    (Proof of Solar 1MWh generation, energy grants) & proof of cryptographic work by SolarCoin Foundation & algorithm

    Equitable circulation methodology

    Proof of cryptographic work by algorithm

    1 MWh of solar electricity generation

    Value representation


    Windows, Linux & MacOS & Android(soon)

    Operating Systems

    Windows, Linux, MacOS, Android & others





    Largest holder of circulating currency


    SolarCoin Foundation

    Largest holder of reserve currency


    $20 (4 year stable target)

    Market value


    1440 blocks (daily)

    Difficulty adjustment

    2016 (2 weeks)

    §100 SLR

    Initial block reward

    50 BTC


    Hashing Algorithm


    50% every 1 year

    Block reward decay rate

    50% every 4 years

    4 years

    95% public mining done

    17 years

    2040 (estimate based on Solar Energy production)

    95% in circulation by


    LiteCoin source code fork

    Source Code

    Bitcoin original source

    This Wiki Page highlights the primary differences. A Blockchain explorer is here.

  • Are there physical SolarCoins?

    There aren’t any physical SolarCoins in circulation yet. It is possible for people to create them in a fashion similar to physical bitcoins and paper wallets. A physical SolarCoin might look similar to this. The SolarCoin Foundation doesn’t endorse, verify or authenticate any SolarCoin issuer, producer, agency or service related to SolarCoin. A list of non-endorsed service providers including a SolarCoin paper wallet creator is available in the wiki page SolarCoin exchanges and other services.

    NewMockGold_1280x960SolarCoin Stack Small_1280x960

    SolarCoin Pile Large_1280x960

    These images are provided like all content on the site as creative commons with rights of attribution only. Available in high resolution upon request.

Solar Energy

  • Why energy? How is energy related to the economy?
    Energy and knowledge are key resources in the economy. These resources are fundamental to improving life for all of us.
    GDP vs. MTOE (Metric Tons of Oil Equivalent) from The Nature of Value.

    GDP vs MTOE

  • How is 1 MWh (megawatt hour) of energy put into a coin?
    Each SolarCoin in circulation represents 1 MWh of solar electricity generation. Each SolarCoin in electronic form represents the verified and proven work of 1 MWh of solar electricity generated. The idea for creating an energy backed currency is derived from an academic paper; DeKo: An Electricity-Backed Currency Proposal. SolarCoin is designed to help shift the levelized cost of energy (LOCE) in favor of Solar energy.
  • Why Solar energy?
    Generating MegaWatts with solar energy is good for the Planet
    Generating megawatts with solar energy is good for the Planet. Heat is an unavoidable by-product of the energy extracted from non-renewable energy sources. Renewable energy using direct or indirect solar energy are accounted for in the thermal balance of our planet, their use adds minimal heat to the environment. Solar energy is the largest renewable energy source available. Wind, Hydro, Geothermal and Biomass energy sources combined don’t add up to the amount of Solar energy landing on Earth’s surface every day (Source data). In addition, Wind, Hydro, Geothermal and Biomass electricity generally require industrial size implementations to be cost effective. Even small groups or individuals can use PV panels to earn SolarCoin.The cost to capture solar energy is decreasing rapidly as more solar energy systems are deployed. For every doubling of Solar Power deployed, the cost drops an estimated 20% for follow on systems due to experience curve effects. EIA Experience curve Data available here.
  • How does SolarCoin help generate renewable electricity?
    SolarCoin is a monetary incentive for electricity generators which helps to tip the rewards of energy generation in favor of renewable sources rather than fossil fuels. SolarCoin is intended to shift the levelized cost of energy (LOCE) towards solar energy sources.
  • How is renewable electricity generation verified?
    Many electronic and manual methods of verification will evolve for different countries and regimes. All claims for SolarCoin will require meter derived proof from a verified generation source and owner. The SolarCoin community will vet all verification methodologies. These methods will rapidly adapt efficiencies seeking maximum ease of use while preventing fraudulent claims.

    Most electric meters have online APIs and web reporting. These can be integrated with SolarCoin verification methods. Inverter manufacturers, meter companies and large systems integrators are invited to partner with SolarCoin to integrate customer web based reading methodologies with the SolarCoin granting community.

    Most SolarCoins are held reserve in publicly visible non-circulating accounts by the SolarCoin Foundation, an open community project. Over 99% of these coins will be distributed to renewable power generators and renewable energy related projects over the coming years.

  • What is Global Horizontal Irradiance?
    The radiation reaching the earth’s surface can be represented in a number of different ways. Global Horizontal Irradiance (GHI) is the total amount of shortwave radiation received from above by a surface horizontal to the ground. This value is of interest to photovoltaic installations and includes both Direct Normal Irradiance (DNI) and Diffuse Horizontal Irradiance (DIF).


  • How does the SolarCoin generator issuance process work?
    Electricity meter readings and other 3rd party community agreed verification methods ensure that each SolarCoin represents 1 MWh of solar electricity generation. Verification mechanisms will be created by volunteer country coordinators and agreed to by the community. Each method will be created, adapt and operate for increasing ease of use and fraud prevention over time. Methods will vary for residential versus large scale commercial verification claims.
  • How can we trust the SolarCoin Foundation to not dump SolarCoins?
    The SolarCoin Foundation controls circulation to generators. It is made of members of the SolarCoin community. All transferred circulating issuance are publicly announced via a public ledger as well as being able to be monitored in the SolarCoin blockchain.
  • Why is each SolarCoin standardized on 1MWh?
    The megawatt hour (MWh) is a unit of electrical energy equal to work done by one megawatt acting for one hour. One megawatt is equivalent to one thousand kilowatts. The MWh is a recognized physical unit of energy and serves as useful proof of work for equitable and useful SolarCoin distribution.

    Nameplate capacity refers to the intended technical full–load sustained output of a facility such as a power plant. Nameplate capacity is the number registered with authorities for classifying the power output of a power station usually expressed in megawatts (MW).

Claiming SolarCoins

  • How many SolarCoins can I expect to receive annually?
    SolarCoin grants are made at the rate of 15% of Nameplate Capacity.

    The annual calculation is 365 days X 24 hrs X 15% X Your KW Nameplate Capacity. This works out to 1.314 X your installed KW Nameplate Capacity. The initial SolarCoin grant is retroactive to the install date of your facility or Jan 1, 2010; whichever is more recent. Ongoing SLR grants are made every 6 months based the facility install month.

    Various international groups recommend or accept this methodology as a proxy for solar electricity generation.

  • What information or documents do I need to collect to claim SolarCoins?

    To claim your SolarCoin, the following information needs to establish:

    1. You are a valid claimant.

    An email address and first and last name are required; ideally linked to a Facebook,  Linkedin or other social media profile that can be verified.

    2. There is a verified generating facility.

    A digital copy of documentation or a link verifying the nameplate capacity, installation date, location and other information relating to the generating facility.

  • Does this cost me anything?
    There is no cost. Participation in the SolarCoin community and granting process is free.
  • What if my solar facility is off-grid?

    Off-grid facilities are currently eligible for SolarCoin grants at the rate of 15% of Nameplate Capacity provided documentation is submitted verifying the nameplate capacity, installation date and location.

  • Can I claim SolarCoins if I am leasing my system?
    Residents of dwellings or homes acting as generator facilities may claim SolarCoins.

  • Why do grants for generating systems located at residential dwellings go to the resident rather than the facility owner or lease holder?
    Many smaller systems are leased or financed. The SolarCoin mission is to incentivize solar electricity generation. Grants to large generators or firms are important, but so is growing the economic community of SolarCoin participants and holders. Residents of homes with residential generating facilities are often the primary consumers of that power.  The SolarCoin Foundation believes that incentivizing the residential consumer directly creates a larger participating base of SolarCoin users and incentivizes Solar electricity generation.

  • Where can I see a list of all the SolarCoin grants?
    The SolarCoin volunteers are working on building a publicly available database to show the grants, recipients and generating facilities. This information is being privately collected and will be made publicly available in a limited fashion only upon confirmation with the grant recipients.

    Every consideration is being made to strike the balance needed to respect individual privacy with transparency for the community to prevent fraud and build trust.  Grants are of course visible with a confirmation ID in the Blockchain.

  • What is the confirmation transaction ID how is it read?
    The confirmation transaction ID is a message put in the block chain for each grant. The format for the message is as follows:

    Lisa Smith example raw data concatenation for Grant Transaction GUID

    Transfer type Country code Post code Generator UID Nameplate capacity Claimant UID Facility Interconnection Date Last Grant Issued Date
    GRT US 85032 01 5.64 01 2011-07-01 2013-07-01

    Final blockchain message Transaction example GUID=  GRT-US-85032-01-5.64-01-2011/07/01-2013/07/01

    Transaction GUID ontology & taxonomic design principles:

    The transaction GUID is organized from most general to specific & from most stable to highly variable factor.

    The transaction message GUID will be separated by “-”s

    - Type of transfer from the generator or genesis pool GRT (for grant) a 3 letter convention will allow for further TLD (Three Letter Declarations in the chain later).

    - Generator UID:

     – Country (http://en.wikipedia.org/wiki/ISO_3166-2)

     – Post code country specific standard (http://en.wikipedia.org/wiki/Postal_code)

     – UID (assigned by database incrementally subject to country and post-code) this allows for an (I was first in my area) etc. claim.

     – Nameplate capacity (declared in KW at the point and time of interconnect or most recent update if expanded/damaged.)

     – Claimant UID:

     – UID (assigned incrementally by database)

     – Dates:

     – Using ISO convention from most to least significant (yyyy/mm/dd)

    Note: The claim amount is not included as it is implicit in the transaction amount at 1SLR to 1MWh and will be found as the transfer amount with the transaction ID in the blockchain.

  • Is my claimant information kept private?

    Participating in the granting program is voluntary and the default is to keep all information private. Upon completion of the program, a request will be sent to make some information public. You may opt out of this request and still retain your SolarCoins.

  • What countries are participating and what languages are supported?
    Volunteers are verifying all countries. Volunteers are encouraged to sign up or participate in their countries section of the SolarCoin Forum to speed the claim development process and technology build out.
    SolarCoins have been granted to 14 out of 215 countries so far. Claim SolarCoins here.
    The SolarCoin website and services support most major languages. Click on the Flag representing your country in the bottom right corner of this page.