There are some other ways too. I have used the following script:

$File = "D:\Dev\somefilename.zip";
$ftp = "ftp://username:password@example.com/pub/incoming/somefilename.zip";

Write-Host -Object "ftp url: $ftp";

$webclient = New-Object -TypeName System.Net.WebClient;
$uri = New-Object -TypeName System.Uri -ArgumentList $ftp;

Write-Host -Object "Uploading $File...";

$webclient.UploadFile($uri, $File);

And you could run a script against the windows FTP command line utility using the following command

ftp -s:script.txt 

(Check out this article)

The following question on SO also answers this: How to script FTP upload and download?

Easiest way

The most trivial way to upload a binary file to an FTP server using PowerShell is using WebClient.UploadFile:

$client = New-Object System.Net.WebClient
$client.Credentials =
    New-Object System.Net.NetworkCredential("username", "password")
$client.UploadFile(
    "ftp://ftp.example.com/remote/path/file.zip", "C:\local\path\file.zip")

Advanced options

If you need a greater control, that WebClient does not offer (like TLS/SSL encryption, etc), use FtpWebRequest. Easy way is to just copy a FileStream to FTP stream using Stream.CopyTo:

$request = [Net.WebRequest]::Create("ftp://ftp.example.com/remote/path/file.zip")
$request.Credentials =
    New-Object System.Net.NetworkCredential("username", "password")
$request.Method = [System.Net.WebRequestMethods+Ftp]::UploadFile 

$fileStream = [System.IO.File]::OpenRead("C:\local\path\file.zip")
$ftpStream = $request.GetRequestStream()

$fileStream.CopyTo($ftpStream)

$ftpStream.Dispose()
$fileStream.Dispose()

Progress monitoring

If you need to monitor an upload progress, you have to copy the contents by chunks yourself:

$request = [Net.WebRequest]::Create("ftp://ftp.example.com/remote/path/file.zip")
$request.Credentials =
    New-Object System.Net.NetworkCredential("username", "password")
$request.Method = [System.Net.WebRequestMethods+Ftp]::UploadFile 

$fileStream = [System.IO.File]::OpenRead("C:\local\path\file.zip")
$ftpStream = $request.GetRequestStream()

$buffer = New-Object Byte[] 10240
while (($read = $fileStream.Read($buffer, 0, $buffer.Length)) -gt 0)
{
    $ftpStream.Write($buffer, 0, $read)
    $pct = ($fileStream.Position / $fileStream.Length)
    Write-Progress `
        -Activity "Uploading" -Status ("{0:P0} complete:" -f $pct) `
        -PercentComplete ($pct * 100)
}

$ftpStream.Dispose()
$fileStream.Dispose()

Uploading folder

If you want to upload all files from a folder, see
PowerShell Script to upload an entire folder to FTP

I recently wrote for powershell several functions for communicating with FTP, see https://github.com/AstralisSomnium/PowerShell-No-Library-Just-Functions/blob/master/FTPModule.ps1. The second function below, you can send a whole local folder to FTP. In the module are even functions for removing / adding / reading folders and files recursively.

#Add-FtpFile -ftpFilePath "ftp://myHost.com/folder/somewhere/uploaded.txt" -localFile "C:\temp\file.txt" -userName "User" -password "pw"
function Add-FtpFile($ftpFilePath, $localFile, $username, $password) {
    $ftprequest = New-FtpRequest -sourceUri $ftpFilePath -method ([System.Net.WebRequestMethods+Ftp]::UploadFile) -username $username -password $password
    Write-Host "$($ftpRequest.Method) for '$($ftpRequest.RequestUri)' complete'"
    $content = $content = [System.IO.File]::ReadAllBytes($localFile)
    $ftprequest.ContentLength = $content.Length
    $requestStream = $ftprequest.GetRequestStream()
    $requestStream.Write($content, 0, $content.Length)
    $requestStream.Close()
    $requestStream.Dispose()
}

#Add-FtpFolderWithFiles -sourceFolder "C:\temp\" -destinationFolder "ftp://myHost.com/folder/somewhere/" -userName "User" -password "pw"
function Add-FtpFolderWithFiles($sourceFolder, $destinationFolder, $userName, $password) {
    Add-FtpDirectory $destinationFolder $userName $password
    $files = Get-ChildItem $sourceFolder -File
    foreach($file in $files) {
        $uploadUrl ="$destinationFolder/$($file.Name)"
        Add-FtpFile -ftpFilePath $uploadUrl -localFile $file.FullName -username $userName -password $password
    }
}

#Add-FtpFolderWithFilesRecursive -sourceFolder "C:\temp\" -destinationFolder "ftp://myHost.com/folder/" -userName "User" -password "pw"
function Add-FtpFolderWithFilesRecursive($sourceFolder, $destinationFolder, $userName, $password) {
    Add-FtpFolderWithFiles -sourceFolder $sourceFolder -destinationFolder $destinationFolder -userName $userName -password $password
    $subDirectories = Get-ChildItem $sourceFolder -Directory
    $fromUri = new-object System.Uri($sourceFolder)
    foreach($subDirectory in $subDirectories) {
        $toUri  = new-object System.Uri($subDirectory.FullName)
        $relativeUrl = $fromUri.MakeRelativeUri($toUri)
        $relativePath = [System.Uri]::UnescapeDataString($relativeUrl.ToString())
        $lastFolder = $relativePath.Substring($relativePath.LastIndexOf("/")+1)
        Add-FtpFolderWithFilesRecursive -sourceFolder $subDirectory.FullName -destinationFolder "$destinationFolder/$lastFolder" -userName $userName -password $password
    }
}

You can use this function :

function SendByFTP {
    param (
        $userFTP = "anonymous",
        $passFTP = "anonymous",
        [Parameter(Mandatory=$True)]$serverFTP,
        [Parameter(Mandatory=$True)]$localFile,
        [Parameter(Mandatory=$True)]$remotePath
    )
    if(Test-Path $localFile){
        $remoteFile = $localFile.Split("\")[-1]
        $remotePath = Join-Path -Path $remotePath -ChildPath $remoteFile
        $ftpAddr = "ftp://${userFTP}:${passFTP}@${serverFTP}/$remotePath"
        $browser = New-Object System.Net.WebClient
        $url = New-Object System.Uri($ftpAddr)
        $browser.UploadFile($url, $localFile)    
    }
    else{
        Return "Unable to find $localFile"
    }
}

This function send specified file by FTP. You must call the function with these parameters :

• userFTP = "anonymous" by default or your username
• passFTP = "anonymous" by default or your password
• serverFTP = IP address of the FTP server
• localFile = File to send
• remotePath = the path on the FTP server

For example :

SendByFTP -userFTP "USERNAME" -passFTP "PASSWORD" -serverFTP "MYSERVER" -localFile "toto.zip" -remotePath "path/on/the/FTP/"

Simple solution if you can install curl.

curl.exe -p --insecure  "ftp://<ftp_server>" --user "user:password" -T "local_file_full_path"