Community Solar Fund Contract

What it does:
Enables communities to collectively fund, own, and benefit from shared solar energy projects through transparent on-chain investment and revenue distribution.

Why it matters:
Lowers the barrier to renewable energy ownership, democratizes access to clean power, and ensures fair, auditable distribution of returns from solar projects.

How it works:

Community members contribute funds to a shared solar project
Contributions are recorded on-chain and represent ownership shares
Funds are used to deploy or expand solar installations
Energy revenue or savings are periodically reported via oracles
Smart contract distributes收益 to contributors proportional to shares
Governance decisions (maintenance, expansion) can be community-voted
All funding, ownership, and payouts are transparent and auditable

      // SPDX-License-Identifier: MIT
pragma solidity ^0.8.20;

import "@openzeppelin/contracts/access/Ownable.sol";
import "@openzeppelin/contracts/token/ERC20/IERC20.sol";

/**
 * @title CommunitySolarFund
 * @author Nam
 * @notice Collective funding and revenue sharing for community solar projects
 */
contract CommunitySolarFund is Ownable {

    IERC20 public payoutToken;

    uint256 public totalShares;
    uint256 public totalRevenue;

    mapping(address =&gt; uint256) public shares;
    mapping(address =&gt; uint256) public claimedRevenue;

    // -------------------- EVENTS --------------------

    event ContributionReceived(address indexed contributor, uint256 amount, uint256 sharesMinted);
    event RevenueReported(uint256 amount);
    event RevenueClaimed(address indexed contributor, uint256 amount);

    // -------------------- CONSTRUCTOR --------------------

    constructor(address _payoutToken) {
        payoutToken = IERC20(_payoutToken);
    }

    // -------------------- FUNDING --------------------

    function contribute(uint256 _amount) external {
        require(_amount &gt; 0, "Invalid amount");

        payoutToken.transferFrom(msg.sender, address(this), _amount);

        uint256 mintedShares = _amount; // 1:1 for simplicity
        shares[msg.sender] += mintedShares;
        totalShares += mintedShares;

        emit ContributionReceived(msg.sender, _amount, mintedShares);
    }

    // -------------------- REVENUE REPORTING --------------------

    function reportRevenue(uint256 _amount) external onlyOwner {
        require(_amount &gt; 0, "Invalid revenue amount");

        payoutToken.transferFrom(msg.sender, address(this), _amount);
        totalRevenue += _amount;

        emit RevenueReported(_amount);
    }

    // -------------------- REVENUE CLAIM --------------------

    function claimRevenue() external {
        uint256 userShare = shares[msg.sender];
        require(userShare &gt; 0, "No shares owned");

        uint256 entitled = (totalRevenue * userShare) / totalShares;
        uint256 claimable = entitled - claimedRevenue[msg.sender];
        require(claimable &gt; 0, "Nothing to claim");

        claimedRevenue[msg.sender] += claimable;
        payoutToken.transfer(msg.sender, claimable);

        emit RevenueClaimed(msg.sender, claimable);
    }
}